I began working on an .Net Core solution in VS 2015, which contains an ASP.Net Core project and a couple of .Net Core class libraries. The solution was under TFS source control.
I wanted to include some unit tests. Since .Net Core unit test project templates are not included with VS 2015, I decided to install VS 2017 and upgrade the solution. After upgrading, I was able to add a unit test project and everything compiles and runs normally.
When I first opened the solution after upgrading, though, I initially got an error about the solution being treated as though it was not under source control. Based on Google searches, I went into File -> Source Control -> Advanced -> Change Source Control and clicked "Bind" on each project. The three old projects link right up and show up as "Valid", while the solution file and the new unit test project show up as "Invalid". Unbinding, unloading, reloading, and rebinding the invalid project did not help. I can force the project to bind even though it is invalid (against Visual Studio's warnings), and after some tinkering, I can get the solution to check in, but when I get latest on another machine, the three original projects say "Not Available" and the unit test project is not visible.
Other symptoms: project.json is not found when I try to check in (I have to "undo" or "exclude" to check the solution in) and regardless of what I try, the invalid unit test project's folder shows up in the root folder of the directory tree (at the same level as "src" and "Backup") while the valid projects are in the "src" directory. I am inferring this is because the new solution types allow an .xproj file, while the old solutions required project.json, but I don't know what to do about it...
Any ideas on how to relink this to source control would be appreciated! I did not upgrade TFS server when I upgraded VS, but I don't directly have access to it, so hopefully this is not a requirement...
To fix the invalid binding in VS, you could try to follow below steps:
Click the “invalid” project in Solution Explorer.
Open “File | Source Control | Change Source Control”
Unbind the invalid project.
In Solution Explorer, Unload the project.
In Solution Explorer, Reload the project.
Also clear TFS and VS cache, delete the old workspace, create a new one, get all projects you need from TFS source control. Everything should be back on track.
Sledgehammer approach not normally needed, just Delete the contents from the following folder
C:\Users\<<Your Alias>>\AppData\Local\Microsoft\Team Foundation
Do not delete the rest unless necessary, fix the cause not the symptom.
My issue was that the project name had a period '.' in it. Removed it and the change source control Bind was Valid.
I tried all the solution above and none of them worked for me.
But I found a way to force add project. In Visual Studio :
Go to team explorer
Click on Home
Click on Source Control Explorer
Select the directory and click on "Add Items to Folder" (the icon is a file with a little green + in the top left corner)
Add your project files
... problem solved
All .cs file in my Xamarin project are Miscellaneous files http://prntscr.com/cp3q4w . I have no Quick Actions and Refactorings support, and it seems like there is somehow missing reference to Xamarin.Forms http://prntscr.com/cp3qzr ,but i dont get compile error for not recognizing xamarin components.
This is Xamarin.Forms Shared project.
Tried with this solution:
i) Clear the cache
ii) Open the solution
iii) Unload all projects
iv) Load Android project and then fix nuget references
v) Once the references were fixed, I loaded the shared project. Now everything seems to work.
But, didn't succeed.
Anyone had similar problem? Any suggestions for solution?
Thanks.
First thing to try if your solution is checked in to source control:
Do a full Git clean to make sure there are no left over files stopping compilation
Clear your NuGet cache. (How to clear NuGet package cache using command line?)
Try again.
If this fails, try this:
Starting a new Visual C# -> Cross Platform -> Mobile App (Xamarin.Forms) solution in Visual Studio 2017. I recommend trying a ".NET Standard" project rather than a "Shared Project".
Make sure the solution compiles and runs to make sure you have all the necessary components for Xamarin Installed.
Do a back up of this clean solution, or commit it to source control.
Upgrade all the NuGet packages if necessary
Pull all the files in from your old solution and see if you get the same problem. Just remember to make sure that the files are added as the correct type of file. For example xaml files must be set to "Embedded resource".
If you still have trouble, please post the error that you get, and upload your solution somewhere so we can have a look.
This also happened to me.
It still does every now and again.
These steps work for me:
Close your solution.
Delete the packages folder from your solution folder or just rename it to packages.old
Open your solution and restore the NuGet packages.
The new class will now show up correctly and your intellisense should work again.
Does anyone have an idea what could cause this though as I don't see any errors when building?
I have a large solution in Visual Studio 2012 which consists of executables and class library projects.
When debugging the application the breakpoints in one particular class library project are not being hit.
I looked at the Debug> Windows> Modules window to check the status of the symbols for that project and it says "Cannot find or open the PDB file".
It also says "No" under the "User Code" column.
I notice that there are a few other of the custom projects in the solution that are showing "No" in that column and their symbols are also failing to load. Anything with a "Yes" under "User code" seems to have had it's pdb loaded no problem. But I'm not sure if this is relevant.
I have used dumpbin /headers on the dll and the path for the pdb file is present and correct.
The module is definitely not in the exclude list for the symbol loading.
I have also tried right clicking on the entry in the modules window, selecting "Load symbols" and navigating to the path given in the dll header. When I select the pdb it says "A matching symbol file was not found in this folder".
I get this after I have deleted these folders and files, cleaned the solution, closed it and rebuilt the whole thing.
The pdb was definitely built at the same time as the dll in question.
So clearly the problem is the "cannot open the pdb" portion of the error message.
I have tried this on 2 computers and both are exhibiting the same behaviour.
Can anyone offer any suggestions on where to go from here, and perhaps why on earth the built pdb corresponding to the dll won't load for it?
I tried a few tools to check if the pdb and the dll actually matched, and using chkmatch I could see that the GUIDs in the dll being run and the pdb in the obj folder didn't match.
So it turns out that although the dll and pdb in the project's obj folder are a match, the dll that was actually getting copied to the application's destination folder by a post-build event was the old dll from the previous build.
The post-build event was running before that particular project had built, or at least finished building, and was copying in the existing dll from the bin which was subsequently overwritten by the continuing build.
I have resolved the problem by editing the project dependencies for the solution and ensuring that the project with the post-build event is dependent on the project that wasn't loading, and now the pdb loads during debug.
I simply deleted bin and obj folder from the startup project folder and rebuild the solution.
For me I just deleted the project from IIS and created it again and it works fine
For me it helped to use chkmatch tool and then just close and open visual studio, make clean and rebuild. Now my pdb gets also loaded. You can make sure it does, as Nanhydrin pointed out, from Debug -> Windows -> Modules - this view is only accessible during debugging.
I found that the project I was receiving the message about, was being optimized when built.
I went into the projects properties, Compile Tab, Advanced Compile Options... and unchecked the Enable Optimizations checkbox
In my case older version of referenced dll was in my GAC. Cleared it out, and it worked.
In my case there was a check mark on Enable Just My Code in Tools>>Options>>Debugging>>General.
I unchecked it and it worked.
Example Image
Reminder: Put the project into "Debug" configuration... for those like me who forget and feel silly.
I just had this issue and thought I would put my fix here, as it my help others (maybe even myself again?!) in the future...
Make sure that when you are attaching to the process on the remote server, that the "Attach to" is set to
Automatically determine the type of code to debug
To do this, When the server qualifier has been provided and a list of processes is visible, click the "Select" button next to the "Attach to" input.
Then, select "Automatically determine the type of code to debug" and OK out of the screen, then attach.
This fixed the issue for me, at least.
Deleted the project from solution and added it again to the solution worked for me. :)
Bit late to the party here - just in case this is helpful.
We have a couple of separate websites (in different solutions in Visual Studio). On initial load of one of the sites, we were making a call to the other site which would return an image.
Both of these sites referenced a common DLL, but while working on one site, had not realised that the other site had been left in a 'Release' build - after the site loaded, the offending DLL was rebuilt, but without symbols.
Kudos to Nanhydrin for both mentioning the modules debug window (very helpful) and for putting me on the right track with the post build event.
Answer from another thread that worked for me: https://stackoverflow.com/a/28476665/5969306
- In Visual Studio: Project Properties -> Build -> Advanced button -> Debug info drop-down and make sure the value is not “none”.
I had a line like this in my debug window:
Symbols for the module 'MyModule.dll' were not loaded.
I removed the 'Optimize code' option in Project properties -> Build. And the error disappeared.
This issue may be due to wrong reference of dlls used in project.
Delete obj and bin folders in current project and build project again.
Check for permission to ASP.NET Temporary folder:
"c:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files"
User of application pool has to have the rights to subfolder with ASP.NET files, something like:
root\60039743\c28e12ee
Check options from this answer: https://stackoverflow.com/a/38377530/6911991
Click Advanced and check that Debugging Information is set to FULL
Check Run Configuration in all projects in the solution
I had this issue , tried all the other solutions (it took 2 days !! I'm crying... !TWO DAYS!) But finally I realized that my file was registered in GAC, I removed it and the problem was resolved.
At the command prompt, type the following command:
gacutil –u <assembly name>
How to: Remove an Assembly from the Global Assembly Cache
Please check the dependency of your dll, if you added to the solution, this can cause failure in loading symbols.
I resolved this issue by disabling 'Use Managed Compatibility Mode' in the Debug->Options menu:
For some reason, visual studio (2012) is not reading any changes in my code. It will recognize an error but, for example, if I get rid of something that makes a window appear, a window will still appear. I am also unable to debug my code (I get the 'symbols not loaded for this document' error). This has been going on for a few days.
I'm not quite sure what to do. I've cleared the visual studio cache but that didn't help. I've changed the startup project settings around but that doesn't change anything either. This is all from my local machine (no source/version control). Does anyone know why this is?
I fixed this by deleting the .suo (silverlight user options) file, as was suggested in the link below, thanks #amalgamate
http://www.kunal-chowdhury.com/2011/08/why-visual-studio-debugger-is-not.html
Try Build > Clean Solution then Build
This may not be your answer and I do not know silver light, but I have found the symbols not loaded error often when the solution file lost track of where a project file was, or when a project file lost track of a library. Maybe the file is missing, or maybe someone else on your team directed it else where etc.. To fix this in project explorer, right click on the solution or project and re-add the particular reference or project (using the add menu item). You may then have to remove the old project/ or reference. You will know the references and projects are bad because of the icon next to them in the project explorer. The bad links will also be listed in the output of your build with the bad links named.
I am working on a WPF, C# 3.0 project, and I get this error:
Error 1 Metadata file
'WORK=- \Tools\VersionManagementSystem\BusinessLogicLayer\bin\Debug
\BusinessLogicLayer.dll' could not be found C:\-=WORK=- \Tools
\VersionManagementSystem\VersionManagementSystem\CSC VersionManagementSystem
This is how I reference my usercontrols:
xmlns:vms="clr-namespace:VersionManagementSystem"
<vms:SignOffProjectListing Margin="5"/>
It happens after every failed build. The only way I can get the solution to compile is to comment out all my user controls and re-build the project, and then I uncomment the usercontrols and everything is fine.
I have checked build orders and dependencies configurations.
As you can see, it seems to have truncated the DLL file's absolute path... I have read that there is a bug with the length. Is this a possible problem?
It's very annoying and having to comment, build, and uncomment, the build is becoming extremely tiresome.
I just had the same problem. Visual Studio isn't building the project that's being referenced.
Written Instructions:
Right click on the solution and click Properties.
Click Configuration on the left.
Make sure the check box under "Build" for the project it can't find is checked. If it is already checked, uncheck, hit apply and check the boxes again.
(Optional) You had to do it for both Release and Debug modes on the solution properties.
Screen capture Instructions:
They say a picture is worth a thousand words. Click on the GIF to zoom in, and hopefully it will be easy to follow:
This can still happen in newer versions of Visual Studio (I just had it happen on Visual Studio 2013):
Another thing to try is to close Visual Studio and delete the .suo file that is next to the .sln file. (It will be re-generated the next time you Save all (or exit Visual Studio)).
I've had this problem when adding new projects to the solution on another machine and then pulling the revisions in, but the .suo file can be corrupted in other cases as well and lead to very strange Visual Studio behaviour, so deleting it is one of the things I always try.
Note that deleting the .suo file will reset the startup project(s) of the solution.
More on the .suo file is here.
The suggested answer did not work for me. The error is a decoy for another problem.
I found out that I was targeting a slightly different version of .NET and this was flagged as a warning by the compiler, but it was causing building to fail.
This should have been flagged as an error and not a warning.
Well, my answer is not just the summary of all the solutions, but it offers more than that.
Section (1):
In general solutions:
I had four errors of this kind (‘metadata file could not be found’) along with one error saying 'Source File Could Not Be Opened (‘Unspecified error ‘)'.
I tried to get rid of ‘metadata file could not be found’ error. For that, I read many posts, blogs, etc. and found these solutions may be effective (summarizing them over here):
Restart Visual Studio and try building again.
Go to 'Solution Explorer'. Right click on Solution. Go to Properties. Go to 'Configuration Manager'. Check if the checkboxes under 'Build' are checked or not. If any or all of them are unchecked, then check them and try building again.
If the above solution(s) do not work, then follow sequence mentioned in step 2 above, and even if all the checkboxes are checked, uncheck them, check again and try to build again.
Build Order and Project Dependencies:
Go to 'Solution Explorer'. Right click on Solution. Go to 'Project Dependencies...'. You will see two tabs: 'Dependencies' and 'Build Order'. This build order is the one in which solution builds. Check the project dependencies and the build order to verify if some project (say 'project1') which is dependent on other (say 'project2') is trying to build before that one (project2). This might be the cause for the error.
Check the path of the missing .dll:
Check the path of the missing .dll. If the path contains space or any other invalid path character, remove it and try building again.
If this is the cause, then adjust the build order.
Section (2):
My particular case:
I tried all the steps above with various permutations and combinations with restarting Visual Studio a few times. But, it did not help me.
So, I decided to get rid of other error I was coming across ('Source File Could Not Be Opened (‘Unspecified error ‘)').
I came across a blog post: TFS Error–Source File Could Not Be Opened (‘Unspecified error ‘)
I tried the steps mentioned in that blog post, and I got rid of the error 'Source File Could Not Be Opened (‘Unspecified error ‘)' and surprisingly I got rid of other errors (‘metadata file could not be found’) as well.
Section (3):
Moral of the story:
Try all solutions as mentioned in section (1) above (and any other solutions) for getting rid of the error. If nothing works out, as per the blog mentioned in section (2) above, delete the entries of all source files which are no longer present in the source control and the file system from your .csproj file.
In my case it was caused by a .NET Framework version mismatch.
One project was 3.5 and the other referencing project 4.6.1.
Visual Studio 2019 this worked for me:
Close Visual Studio
Delete the hidden .vs folder
Reopen Visual Studio and rebuild the solution.
Closing and reopening Visual Studio 2013 worked for me!
Well, nothing in the previous answers worked for me, so it got me thinking about why am I clicking and hoping when as developers we should really try to understand what is going on here.
It seemed obvious to me that this incorrect meta data file reference must be held somewhere.
A quick search of the .csproj file showed the guilty lines. I had a section called <itemGroup> that seemed to be hanging onto the old incorrect filepath.
<ItemGroup>
<ProjectReference Include="..\..\..\MySiteOld\MySite.Entities\MySite.Entities.csproj">
<Project>{5b0a347e-cd9a-4746-a3b6-99d6d010a6c2}</Project>
<Name>Beeyp.Entities</Name>
</ProjectReference>
...
So a simple fix really:
Backup your .csproj file.
Find the incorrect paths in the .csproj file and rename appropriately.
Please make sure you backup your old .csproj before you fiddle.
In my case, I have my installed directory in mistaken ways.
If your solution path is something like "My Project%2c Very Popular%2c Unit Testing%2c Software and Hardware.zip", it cannot resolve the metadata file, perhaps we should prevent some invalid words like %2c.
When a repository is cloned from certain sites, the directory name is URL encoded. Which would convert space characters in directory names to %20, forward slashes to %2f, underscores to %5f, etc. Although, I'm not sure why the % symbol is breaking things.
Renaming the path into a normal name resolved my issue.
I also met this problem. Firstly you have to manually build you DLL project, by right-click, Build. Then it will work.
In my case, the problem was caused by a simple build error,
error CS0067: The event 'XYZ' is never used
that, for any reason, did not show up in the error window.
Because of that, the Visual Studio build system seemed to miss the error and tried to build dependent projects, which in turn failed with the annoying metadata message.
The recommendation is -as stupid as it may sound-:
First look at your Output Window!
It took me half an hour before this idea hit me...
I got the same error "Metadata file '.dll' could not be found", and I tried several things described above, but the reason for the error was that I was referencing third-party DLL file which was targeting a .NET version higher that my project target .NET version. So the solution was to change the target framework of my project.
I added a new project to my solution and started getting this.
The reason? The project I brought in was targeting a different .NET framework (4.6 and my other two were 4.5.2).
For me, it was trying to find a DLL in a path that used to contain the Project, but we'd moved it to a new directory. The Solution had the correct path to the Project, but Visual Studio somehow kept looking in the old location.
Solution: Rename each problem Project - just add a character or whatever - then rename it back to its original name.
This must reset some global cache of some kind in Visual Studio, because this clears both this issue up and several like it, while things like Clean do not.
It looks like such kind of errors related to the fact that Visual Studio doesn't provide correct information about an error. The developer doesn't even understand the reason for the failed build. It can be a syntax error or something else. In common, to solve such problems you should find the root of the problem (for example, look at the build log).
In my case the problem was in fact that the Error List window didn't show any errors. But really there were syntax errors; I found these errors in the Output window, and after fixing them, the problem was solved.
For me it occurred when I included a new project to a solution.
Visual Studio automatically selects .NET framework 4.5.
I changed to version .NET 4.5.2 like the other libraries, and it worked.
If you have a space in your solution name, this will also cause the issue. Removing the space from your solution name, so path doesn't contain %20 will solve this.
Coming back to this a few years later, this problem is more than likely related to the Windows maximum path limit:
Naming Files, Paths, and Namespaces, Maximum Path Length Limitation
For me the following steps worked:
Find the project that is not building
Remove/add references to projects within the solution.
I was pulling my hair out with this problem also, but after trying the previous answers the only thing that worked for me was to open each project in my solution 1 by 1 and build them individually.
Then I closed Visual Studio 2013, reopened my solution and it compiled fine.
It's strange, because if I clicked each project in my Solution Explorer and tried to build them that way, they all failed. I had to open them alone in their own solutions.
In my case the issue was that I'd manually deleted a non-compilation file which was marked as "missing". Once I deleted the reference to the now-missing file and recompiled - all was well.
My instance of the problem was caused by a common project that had a duplicate class name in it (under a different filename). It is strange that Visual Studio could not detect that and instead just blew up the build process.
I got this problem in Visual Studio 2012 in a solution that had many projects. Rebuilding each project in the solution manually in the same order as the Project Build Order (right-click and rebuild in Solution Explorer) fixed it for me.
Eventually I got to one that gave me a compile error. I fixed the error, and the solution would build correctly after that.
I too had the same error. It hides as in the below path.
The path which I referred to for the DLL file is like "D:\Assemblies Folder\Assembly1.dll".
But the original path in which the assembly referred was "D:\Assemblies%20Folder\Assembly1.dll".
Due to this path name variation, the assembly could not be retrieved from its original path and hence throws the "Metadata not found" error.
The solution is in Stack Overflow question How do I replace all the spaces with %20 in C#?.
Most of the methods explained here did not solved the problem for me.
Finally, I fixed the problem by applying the following steps:
1. Close Visual Studio.
2. Delete all the contents in the bin folders of each project.
3. Open solution and rebuild.
I hit and solved this problem today on VS2022 in a solution with a Blazor project.
The underlying problem is that I had introduced a routine C# compilation error
in C# code declared in a .razor file. VS2022 was dropping the display of the error from the Build Error List tab. I found the C# error by scanning the build output in the Output console log tab where my C# error was described as expected.
p.s. In case you are wondering, I had a Unit Test project referencing my Blazor web project. The project DLL reference from the Unit Test project to the Blazor app was complaining about the missing Blazor DLL.
Based on the error message I don't believe the file path is being truncated. It looks to just be incorrect. If I'm reading the message correctly it appears to be looking for the DLL file at ...
WORK=-\Tools\VersionManagementSystem\BusinessLogicLayer\bin\Debug\BusinessLogicLayer.dll
This is not a valid path. Is it possible that you have a macro definition in the build process set to an invalid value?
I'd faced the same problem. In my case I'd referenced to a class library project with higher .Net version than my project and VS failed to build the project and raised the same error you posted.
I simply set .Net version of my class library project(the one that had broken the build) identical to the .Net version of referenced project and problem solved.
Just pointing out the blatantly obvious: if you don't have "Show output window when build starts" enabled, make sure you're noticing if your build is failing (small "build failed" error in lower left)!!!!
I had this error when I was trying to publish a web application. Turned out that one of a class properties was wrapped into
#if DEBUG
public int SomeProperty { get; set; }
#endif
but the property usage was not. The publishing was done in Release configuration without the DEBUG symbol, obviously.