We Keep Coding

Cannot find assembly Mono.Android when attempting to archive a Xamarin app for publishing

I had to do some work on a Xamarin project I didn't create that is currently in production. I can build the app in Debug and Release on both Android and iPhone, as can anyone else who clones the repo. However, no one on my team has been able to successfully archive the app for publishing. Everyone gets the same error: Could not resolve this reference. Could not locate the assembly "Mono.Android". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors.
Question 1: Where exactly should Mono.Android exist on disk?
Could not locate the assembly "Mono.Android". Check to make sure the assembly exists on disk
In the projects .Droid folder in the references folder Mono.Android does exist but apparently this isn't enough. Where else should it exist if this is not the only place?
On Windows people say to look in something like C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\Common7\IDE\ReferenceAssemblies\Microsoft\Framework\MonoAndroid{VERSION NUMBER}\Mono.Android.dll but I am on Mac, so where might this be instead?
Question 2: Why exactly am I getting this error in the first place?
Whatever the problem is I don't understand why it would trigger when trying to archive only the .IOS project. As far as I know this shouldn't have anything to do with Mono.Android. I feel like I should only be getting this error when I try to archive the .Droid project.
Question 3: What solutions are there to this?
Requires minimum Android version: 6 (API level 23)
Target Android version: 9.0 (API level 28)
Everyone on the team is using VS for Mac.
I have confirmed that I have Android 9 Pie installed and with all it's packages. I have attempted to archive for publishing on both Visual Studio for Mac 2019 and 2022 but got the same result for each. I have had others on the team attempt the same.
I have attempted to re-reference Mono.Android but when I try to add a reference and I scroll down to Mono.Android the version is 0.0.0.0. Why would that be?
What am I missing and how do I get it?
If you need any additional information please ask and I'll do my best to share.

I finally successfully deployed the app. I found a hardcoded path to Mono.Android in the Droid project csproj file. I removed this and the Mono.Android error stopped, but I was still getting similar errors so this is what happened:
I believe that the app was originally developed in VS for Mac 2017 and used whatever Xamarin package versions came with whatever version of VS for Mac 2017 the app was developed in. I am using an M1 Mac and cannot install VS for Mac 2017 or a lot of the packages that I needed. So what I did was moved to VS for Mac 2022 and upgraded all Xamarin packages and then fixed the errors that arose from that.
Once all packages were upgraded the app still would not deploy properly so I downloaded Transporter and used that to deploy the app which was very easy.
I hope this helps someone in the future.

CefSharp WPF Error

Have used CefSharp to use the chromium web browser in a WPF project. The build works as expected, but when published, the error received is:
The invocation for the constructor on type 'CefSharp.Wpf.ChromiumWebBrowser' that matches the specific binding constraints threw an exception.' Line number '24' and line position '15'. IsTerminating:True
Have followed the advise here:
https://github.com/cefsharp/CefSharp/issues/2030
Which unfortunately has not yielded any results, have also followed the read me here:
https://github.com/cefsharp/cef-binary/blob/master/README.txt#L82
The files exist in the published directory, but in the event viewer, the error:
Application: APP.exe Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.IO.FileNotFoundException at CefSharp.Wpf.ChromiumWebBrowser.NoInliningConstructor() at CefSharp.Wpf.ChromiumWebBrowser..ctor()
Any assistance appreciated, as am not sure where else to look to resolve.

You should install vc++ redist 2013(x86 or x64) on the target computer.
vc++ redist 2015 doesn't work.
Download available from here:
Visual C++ Redistributable Packages for Visual Studio 2013

I had this problem after updating the NuGet package. I realized that my installer was copying dependencies from a folder named "Needed" where I had previously painstakingly collected all of the files needed to run the application (with lots of unmanaged things). So when I ran the exe from the build folder it worked fine, but when I installed it, it crashed because all of the DLLs were for the previous version. A quick fix for me was to just copy all of the contents of my build folder to the silly "Needed" folder I had previously made.
Hopefully I'll find this a year from now when it happens again.

CefSharp - Could not load file or assembly 'CefSharp.Core.dll' or one of its dependencies

I've been working on a CefSharp WinForms app for a few weeks and I've had no issues with it. This morning, while adding a few things to the application, I tried to run it to test something and got the below error:
System.IO.FileNotFoundException was unhandled Message: An unhandled
exception of type 'System.IO.FileNotFoundException' occurred in
mscorlib.dll Additional information: Could not load file or assembly
'CefSharp.Core.dll' or one of its dependencies. The specified module
could not be found.
After searching for a while I found this:
https://github.com/cefsharp/CefSharp/wiki/Frequently-asked-questions#Runtime_dependencies
I checked bin/Debug/x86 for the project and all of the dependencies appear to be present. More importantly, it had been working fine five minutes earlier, and I didn't touch anything beyond a single class for an Entity Framework migration.
I've tried cleaning and rebuilding the solution, restarting Visual Studio, restarting my PC, and clearing out /bin/Debug, and none of these have helped.
Why would this error appear now after several days without it, and how can I resolve the issue?
Edit: I've done some further experimenting and I'm able to get the application to run in Release mode but not Debug mode. If I change the output path of Release mode to Debug, it fails with the same error (likewise, it succeeds in Debug with the Release output path).

First, make sure you installed the Microsoft Visual C++ Redistributable:
Version v93 and above: use Microsoft Visual C++ 2019 Redistributable or greater
Version v65 - v92: use Microsoft Visual C++ 2015 Redistributable or greater
Older Versions: use Microsoft Visual C++ 2013 Redistributable (exact version)
You could download the Visual C++ Redistributable from Microsoft. See C++ binary compatibility between Visual Studio versions for more detail on the version compatability.
Make sure to match the correct architecture, if your application is x64, you need to install the x64 build of Visual C++ Redistributable. Likewise if your application is x86 then you need to install the x86 build of Visual C++ Redistributable.
The Microsoft Visual C++ Redistributable depends on the Universal CRT. The Universal CRT is included as part of Windows 10/11. On older versions of Windows the Visual C++ Redistributable will install the Universal CRT.
For those wishing to include the Visual C++ Runtime with their application it's technically possible to include the runtime with your application. See also Local Deployment section of the Deployment in Visual C++ article from Microsoft.

I had the same problem until I installed the following redistributable:

SuperBerry's solution of installing VC++ redistribution package solved the problem for me. I'll just provide a little troubleshooting insights from my naïve perspective.
The error message is pretty clear, either the assemble CefSharp.Core.dll is missing or one of it's dependencies. So the question boils down to how do you figure out what is missing?
So first, do you have CefSharp.Core.dll? In the Solution Explorer look at the references for the project that is having this problem. You should find a reference to CefSharp.Core. If you can't find one, you're missing that assembly. If you have one, then the problem is that you're missing one of its required dependencies. When you click on the CefSharp.Core reference, in the detail, you'll get the full path to where it's located. In my case, it was in located at 'C:\Users\tom\source\repos\MyProject\src\packages\CefSharp.Common.41.0.0\CefSharp\x86\CefSharp.Core.dll'.
You then need to get a list of the CefSharp.Core dependencies to figure out which dependency your missing. Dumpbin.exe is a command line tool that you can use to get a list of dependencies. In order to use dumpbin, you need to make sure that it can be found on the path in your system environment variables. I found on the path of the VC Tools bin directory. In my case, I found one at: 'C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.25.28610\bin\Hostx64\x64'. Open a Command Prompt terminal and navigate to the folder containing CefSharp.Core.dll and key in the following:
>dumpbin /dependents CefSharp.Core.dll
the result I got was:
Dump of file CefSharp.Core.dll
File Type: DLL
Image has the following dependencies:
KERNEL32.dll
MSVCP110.dll
MSVCR110.dll
libcef.dll
USER32.dll
mscoree.dll
Not having worked with Microsoft Visual Studio for a number of years, I had to try and figure out where those dependencies are suppose to be located so that they can be resolved. I simply did an internet search such as "where is Kernel32.dll located" doing that for each dll until I found the missing dll. In my case, I could not find MSVCR110.dll, so I strongly suspected that was my problem. I then did an internet search for "MSVCR110.dll is missing" and found out that it was part of the vc++ redistribution. (SuperBerry, you were right on your first point). I also found that it could be downloaded from: 'https://www.microsoft.com/en-us/download/details.aspx?id=30679'. I downloaded both the x86 and x64 versions (although I only needed the x86 version for this project). They are executables that when run installs them. After installing them I found a copy of it in 'C:\Windows\SysWOW64' and in 'C:/Windows\System32'. And low and behold this problem was resolved.
What I learned from this process, was that it was difficult to know whether you have the right VC++ redistribution package installed or not. I thought I would have been installed when visual studio was installed with the VC++ features enabled. I'm using visual studio community version 2019. The project I am working with was a project I cloned from a GitHub source. I'm still confused about VC++ redistribution versioning. For example, could I have installed some later version and would it have worked (i.e. backward compatibility)?

I had the same issue. what worked for me is to add
<CefSharpBuildAction>Content</CefSharpBuildAction>
to the first PropertyGroup inside the csproj of the project you are dealing with.

I had the same issue even in release mode. Going through GitHub CefSharp FAQs, NOTE 2 solved my issue.
If compiling from source (not recommended, use the Nuget packages) and you notice that you can no longer build in debug mode, but release builds work just fine you may need to repair your version of Visual Studio. This happens in rare cases where you will get the same exact message as a missing unmanaged .dll file as shown above.
Had to repair Visual Studio and all started working as before.

For my future me, had this same issue and every time i get this error when i start my .net core 3.1 wpf application in visual studio -> Could not load file or assembly 'CefSharp.Core.Runtime.
That cost me hours!
My Solution: Don't initialize Cef in your WinForm or WPF Window class.
You need to initialize this in your startup main/app. In my example i need to add this:
public App()
{
CefSettings _browserSettings = new CefSettings();
...
Cef.Initialize(_browserSettings);
}

TFS build process detects error, Visual Studio build process doesn't give an error

My solution can be built properly, with no errors on my workstation while the same source gives an error when building with TFS.
The solution projects target .NET 4.0 and I use VisualStudio 2012 on the workstation.
Using tfs.visualstudio.com (tfspreview.com) to keep the source, which I tried building with the Hosted Build Controller on tfspreview and with my own Build Controller that I host with TFS 2012 on my server.
I get the error in code where I use dynamic ExpandoObject.
Why my solution can't build on TFS?
I can provide more details if needed.

Have you tried the hosted build to see if that works?
Is is definitely the expandoobject? if you comment out that code does the build succeed?
can you send an excerpt from the build log?

I will post this as an answer as it solved this strange problem.
One of the project's solutions had two separate references to same open source library. One to the downloaded precompiled library, and one to another project where I kept the source of the same library. The first one was added by Nuget, the second manually.
The possibility to actually do this (add two references of same assembly) was probably a bug in Visual Studio or Nuget. Later when I tried to reconstruct this bug, an error message appeared, saying there is already reference to the specific assembly name.
For the compiling, I understand that TFS build agent considered only the precompiled assembly (Nuget package) and threw an error.
Visual Studio considered the assembly source which I modified to use with ExpandoObject.
Calling build command manually produced the same error as TFS did.
I removed both references and added only one (the other couldn't be added again anyway). That equalized the build behavior of TFS and VS for my solution.
I know this is very odd and I still can not remember how that double reference bug occurred in the first place. My guess is, this error can be reconstructed by editing the .proj file manually.

LibGit2Sharp fails to find git2.dll

I have built a tiny wpf app that manages a website I am working on. The key feature of this app is that it allows me to checkout different branches of a theme repository. This works perfectly in visual studio, but when I publish, install and run the app on my windows 8 machine it comes back with:
{"Unable to load DLL 'git2': The specified module could not be found. (Exception from HRESULT: 0x8007007E)"}
I have searched through the internet and stackoverflow. There are similar questions, such as Unable to load DLL 'git2.dll' The specified module could not be found but the answers provided (as well as the answers shown in the github issue described in the answer) bring up another error:
Unable to find an entry point git_reference_oid in git2.dll
I have tried installing the latest through nuget, including a compiled dll and adding the git2.dll, including the libgit2sharp project in my solution. Once again, it works perfectly when I run it all through visual studio, but fails when I publish, install and run it.
I was unsure what information needed to be included so please feel free to comment and let me know so I can update the question.
Thank you!

The computer you're running the installed executable on may lack MSVCR100.DLL or MSVCR110.DLL (depending if git2.dll has been compiled using Visual Studio 2010 or 2012).
A fix has been recently merged in libgit2 which removes the need for this dependency.
Indeed, running dumpbin /IMPORTS git2.dll against those binaries doesn't show any dependency against MSVCR1x0.dll any longer.
The latest tip of the vNext branch of the LibGit2Sharp project embeds those updated git2.dlls. It's recommended to compile the project (using the build.libgit2sharp.cmd tool and use this version (manged assembly + native binaries) instead).