Opened an old project from years ago. Build fails because Visual Studio (2019) does not recognize an assembly that is clearly there - specifically, Autofac.
You can see it in project references (not marked as missing)
You can see it in the Object Browser, listing all the types referenced in the code
But in code, none of the types show up, gone AWOL.
What is going on here? Intellisense doesn't even pick up types
(Tried cleaning, rebuilding, re-importing packages)
Okay, this is what worked. I had to remove the reference to the Autofac dll, and then add it back. Note - I added it back from the same exact location, the same exact version. But after this, Visual Studio 'magically' recognized it.
If you come across a similar problem, and nothing else works, give it a try. I don't know the reason, I can only assume this is some sort of a bug in Visual Studio.
I've added the toolkit.dll as a reference, inherited KryptonForm instead of Form, successfully built the application, everything is working fine, but designer mode fail to display the form. I am getting this error:
Could not find type 'ComponentFactory.Krypton.Toolkit.KryptonForm'. Please make sure that the assembly that contains this type is referenced. If this type is a part of your development project, make sure that the project has been successfully built using settings for your current platform or Any CPU.
I found the issue: I renamed the dll thinking that will not affect in any way the application, and it didn't !
But somehow affects the designer: when I renamed the dll back to ComponentFactory.Krypton.Toolkit.dll Visual Studio's designer worked aswell. I am curious why behaves this way
I just reopened a project I haven't touched in a few months, and my copy of VS2012 is doing some strange things. I've seen it do these things before, but usually it works itself out after a Clean or after restarting VS.
I have a Common project, which is referenced by at least 2 other projects in the solution. I have a cs file that contains 2 enums, and a class. I reference those enums within the class, but VS gives me the little red underline that indicates a syntax error.
"The type or namespace name "SourceTypes" could not be found (are you missing a using directive or assembly reference?)"
The enum is literally located above this class. It is public. Also, if I do a build, it will build correctly. But the error comes back after the build finishes. Sometimes it doesn't build properly, and I have to build this project first without doing a build all. I have no idea why this reference has started doing this suddenly.
I also installed CodeMaid and AllMargins recently, but I don't think either of those could cause build errors.
Also, the common library is using Framework 3.5, because it is referenced by two other projects, one of which is SharePoint, and therefore 3.5, and the other of which is a WPF app, running 4.0 (not Client Profile)
Any ideas?
Update: Clearly the problem is that it doesn't recognize the namespace. In the using statement in multiple files, the namespace has the red line under it. Maybe I've got some kind of namespace conflict? But if I did, I would expect it to fail when I do an actual build, which it does not.
Solution: Feri got the right answer. By unloading the Common project, and then reloading it, the problem went away. All references to the namespace were corrected, and everything works smoothly again.
Solution: Feri got the right answer (but opted not to submit his solution as an answer). By unloading the Common project, and then reloading it, the problem went away. All references to the namespace were corrected, and everything works smoothly again. However, the problem seems to come back whenever I close/reopen VS. Unloading/reloading the project fixes it each time though.
I'm using Visual C# 2008 Express. This is the first time I've had this error in years, the last time I had it was around the time I started programming.
I have no idea what it actually means or why it suddenly came up, it seems rather ambiguous for what the error message says. All I know is that throughout my app, I inherit a lot of the main windows from a ThemedWindow class I came up with to give them a custom appearance, there are no errors in that code and everything was working 100% perfect 20 minutes ago.
The error in full:
Warning 12 The designer could not be shown for this file because none of the classes within it can be designed. The designer inspected the following classes in the file:
InheritingWindow --- The base class 'ThemedWindow' could not be loaded. Ensure the assembly has been referenced and that all projects have been built. 0 0
I get that for every form that inherits from ThemedWindow, and several other errors because the project won't build far enough for everything else to work.
Just before this happened I updated the font on all forms and sub-controls, the project even built and ran after I did that, then this happened for absolutely no clear reason.
I've tried the classic rebuild it, delete build files, reopen Visual Studio etc, but nothing seems to work at the moment.
Does anyone know how to fix this?
Build your base usercontrol class with AnyCPU option.
These problems were caused by an unfortunate bug in Visual Studio. I had other errors (not warnings) in some code, even though nothing else directly depended upon it, which played a part in this whole situation.
I could be wrong in explaining it but here's what I think went wrong: for some reason (bug), it totally forgot about unchanged objects it had already compiled before, gave me the actual errors I had in my code, and a bunch of other warnings because it wouldn't go past that point. I couldn't get into the designer for forms that depended upon ThemedWindow because I'm guessing ThemedWindow hadn't recompiled before these errors occurred.
Once I commented out the erroneous code as a quick fix and rebuilt the solution, everything compiled successfully.
As of writing this, this seems to be working properly in VS 2019 16.11.13.
It is not, however, working in VS 2022 17.1.6...
In VS 2022, I tried all the other fixes mentioned here, or they were not relevant:
AnyCPU is already set on the solution, never changed from that
The base class was never modified since it last worked, and so wouldn't need to recompile (plus this seems a moot point since it works fine in VS 2019)
While changing the base class temporarily to System.Windows.Forms.Form did get rid of the original error, it popped up a load of other errors of missing framework references and other non-problems.
The project is referencing .Net 4.8, (latest at time of writing this) and is not different from VS 2019 to VS 2022. Either way, can't reference non-existent newer version, and I doubt referencing an older version would fix this without breaking much more.
I saw a fix somewhere else of running VS as administrator and then rebuilding. This also did not fix the issue.
So I guess my fix for this is to downgrade from VS 2022 to VS 2019...
In my case (VS 2015 Pro) none of the above helped. Only after changing the target framework to different (specifically newer, from 4.5.1 to 4.5.2) and recompiling did the Forms Editor load the form.
Before changing the target framework I tried cleaning the solution, removing and adding the references (the base user control was in different dll), manually deleting all bin and obj folders after cleaning the project, restarting VS, all to no avail...
I have this problem too, with VS 2019 version 16.11.2, so I guess this bug will never be fixed.
My workaround, since my BaseForm class does all its work through code at runtime and has no functionality that would affect the designer, is that when I need to use the designer, I just temporarily change my window's base class. That is, change--
partial class MainWindow : BaseForm {
to
partial class MainWindow : Form {
then do the design stuff, and then once the designer is closed, put BaseForm back.
This may work for you if your base form class also doesn't do anything that would have an effect in the designer.
I have a solution that contains a website and a class library in Visual Studio 2008.
I then have another web site project outside of the solution that needs to reference the class library. I right click the Bin folder or Project and select Add Reference, then select my Class Library Project, it adds the 15 or so DLLs that the class library needs to the websites bin folder, but none of the .cs files recognize the using statements.
using MyLibrary.MyFolder;
It says that it can't resolve it, and ReSharper just says it can be safely removed since it's not being used.
ReSharper can recognize that it needs the reference and suggests that it "Reference MyLibrary and use MyFolder". I'm not sure why it's suggesting I add a reference I already have. When I go with the suggestion, I get the error
"Failed to reference module. Probably, reference will produce circular dependencies between projects."
I've tried going to the websites property pages and removing all the references and re-adding them, but it gives the same errors. Any ideas why this isn't working?
Also, check that the new solution's projects run against a compatible framework to the project you're trying to include. I was trying to include a reference to a 4.0 project in a 3.5 project.
I found how to fix this issue (for me at least). Why it worked, I'm not sure, but it did. (I just tried against a second website that was having the same problem and the following solution worked for that as well).
I tried the normal cleaning of the projects and rebuilding, shutting down all my Visual Studio instances and restarting them, even tried restarting my computer.
What actually worked was opening up the project in Visual Studio, closing all the open tabs, and then shutting it down.
Before I had left the tabs open because I didn't think it mattered (and I hardly ever close the tabs I'm using).
One possibility is that the target .NET Framework version of the class library is higher than that of the project.
I had a similar problem, will all my references being buggered up by Resharper - The solution which worked for me is to clear the Resharper Cache and then restarting VS
tools->options->resharper->options-> general-> click the clear caches button and restart VS
I had a similar problems where VS would sometimes build and sometimes not. After some searching and attempts I discovered that I had an ambiguous reference to a class with the same name in different libraries ('FileManager'). The project that would not build were my Unit Tests that reference all modules in my solution. Enforcing the reference to a specific module sorted things out for me.
My point is: Rather than blaming ReSharper or VS, it may be a good idea to double check if there really isn't some kind of circular reference somehow. More than often, classes with the same names in different modules could cause confusion and is often a symptom of bad design (like in my case).
This sounds like a similar issue with ReSharper:
http://www.jetbrains.net/devnet/thread/275827
According to one user in the thread forcing a build fixes the issue (CTRL+Shift+B) after the first build..
Sounds like an issue with ReSharper specifically in their case.. Have you tried building regardless of the warnings and possible false errors?
Since they are both in the same solution, instead of adding a reference to the DLL, add a reference to the class library project itself (the Add Reference dialog will have a tab for this).
Ahh, it's a different solution. Missed that. How about you try instead of adding a reference to the project addding a reference to the compiled DLL of your class library. The Add Reference dialog has a Browse tab which does this.
After confirming the same version of asp.net was being used. I removed the project. cleaned the solution and re-added the project. this is what worked for me.
If you're referencing assemblies for projects that are in the same solution, add a Project reference (using the "Projects" tab) rather than browsing for the dll in the \bin\Debug (or \bin\Release) folder (using the "Browse" tab). See screen shot below. Only browse for the assembly/dll file if it's considered an external assembly.
I deleted *.csproj.user ( resharper file) of my project, then, close all tabs and reopen it. After that I was able to compile my project and there was no resharper warnings.
I had this problem. It took me ages to figure out. I had people over my shoulder to help. We rebuilt, cleaned and restarted Visual studio and this didn't fix it. We removed and re-added the references...
All to no avail.... Until!
The solution to my problem was that my class declaration was spelt incorrectly.
Before you start judging me harshly, allow me to explain why it wasn't stupid, and also why this mistake could be made by even the most intelligent of programmers.
Since the mistake was early on in the name, it wasn't appearing in the intellisense class listing when I began typing.
e.g.
Class name:
Message.cs
Declaration:
public class Massage
{
//code here
}
At a glance and in a small font, Massage looks identical to Message.
Typing M listed too many classes, so I typed e, which didn't appear in the mistyped version, which gave the impression that the class wasn't being picked up by the compiler.
I had a similar issue in VS 2010, when creating a test project for an MVC 2 application.
The symptoms were identical.
The message from ReSharper was somewhat misleading. For a moment I completely ignored ReSharper and did it the "manual VS way":
I cleaned the solution.
I manually added the reference to the MVC project.
I manually added the using directives.
ctrl-shift-b
At this stage I got a compilation error: I should have referenced the System.Web.Mvc assembly in my test project (sigh). Adding this reference causes the project to compile. The ReSharper issues remain, but the ReSharper test runner works.
When I restart VS, the ReSharper errors are gone too. I'm not sure if the restart is required - simply closing the .cs file might be enough.
From now on, when I see the ReSharper message
Failed to reference module. Probably,
reference will produce circular
dependencies between projects.
I'll read
Failed to reference module. Probably,
reference will produce circular
dependencies between projects,
or you are missing some references to dependencies of the reference's dependencies.
Another possible fix that just worked for me:
If you have Assembly A, which references Assembly B, both of which reference a non-project (external) assembly X, and Assembly B's code will not recognize that you have referenced X, then try the following steps in order:
Drop reference to X from BOTH A and B
Recreate reference to X in B
Recreate reference to X in A
Apparently, VS will not recognize a reference to an external assembly in a project that is a dependency of another project that already references the external. By setting up the references again from the ground up, you overcome this. It's just very odd.
I faced this problem, and I solved it by closing visual studio, reopening visual studio, cleaning and rebuilding the solution. This worked for me.
If using TFS, performing a Get latest (recursive) doesn't always work. Instead, I force a get latest by clicking Source control => Get specific version then clicking both boxes. This tends to work.
If it still doesn't work then deleting the suo file (usually found in the same place as the solution) forces visual studio to get all the files from the source (and subsequently rebuild the suo file).
If that doesn't work then try closing all your open files and closing Visual studio. When you next open Visual studio it should be fixed. There is a resharper bug that is resolved this way.
I had stumbled upon a similar issue recently. I am working in Visual Studio 2015 with Resharper Ultimate 2016.1.2. I was trying to add a new class to my code base while trying to reference a class from another assembly but Resharper would throw an error for that package.
With some help of a co-worker, I figured out that the referenced class existed in the global namespace and wasn't accessible from the new class since it was hidden by another entity of same name that existed in current namespace.
Adding a 'global::' keyword before the required namespace helped me to reference the class I was actually looking for. More details on this can be found on the page listed below:
https://msdn.microsoft.com/en-us/library/c3ay4x3d.aspx
If both projects are contained within the same solution, it will be more apropiate if you add the reference for the project you need, not its compiled dll.
I had the exact same problem.
I tried closing Visual Studio numerous times, I tried deleting and adding a new class library.Checked if I had the right version, if I had referenced it in the target project. Nothing worked.
Then I thought maybe, just maybe I cannot reference the library because it was empty... and that was it.
As soon as I added a class to it the problem was fixed. So if you have tried everything and you are close to losing your sanity. Just try adding something to the class library.
the solution for was just adding the access modifier
my class didnt have any access modifier then i just added public and it worked!
Contracts class library:
namespace Contracts
{
public interface ILoggerManager
{
void LogInfo(string message);
void LogWarn(string message);
void LogDebug(string message);
void LogError(string message);
}
}
Logger service class library:
using Contracts;
using NLog;
public class LoggerManager : ILoggerManager
{
private static NLog.ILogger logger = LogManager.GetCurrentClassLogger();
public LoggerManager()
{
}
}
I tried various solutions for this issue. An old WebForms application refused to acknowledge the existence of a library even though a reference existed.
Oddly, what worked was to add and reference the class library in Visual Studio 2022, safe the project, then reopen in an earlier version of Visual Studio.
My solution was simple, but I'll share it in case someone else has the same issue and finds this question by googling like I did.
It turns out that the most recent build of the supporting DLL was done in Debug mode, and my code was looking at the Release version of the DLL. I rebuilt the DLL in Release mode and all is working properly.
Unfortunately the only thing that worked for me was completely deleting and recreating the class library project, after having temporarily copied the class files in it elsewhere. Only then would the ASP.Net web project recognise the using statements that referred to the class library project. This was with Visual Studio 2010, not using ReSharper.
I had similar issue. What worked for me is that I had added wrong Class Library from visual studio. I added by using the search feature of visual studio.
What I needed to do was Add New Project > Visual C# > Class Library. And this newly added class library is the right one and can now be added as reference to any project.
You may forget to add reference the class library which you needed to import.
Right click the class library which you want to import in (which contains multiple imported class libraries), -->Add->Reference(Select Projects->Solution->select the class library which you want to import from->OK)