Metadata file '.dll' could not be found

Question

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.

Answer 1

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):

1. Restart Visual Studio and try building again.

2. 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.

3. 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.

4. 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.

5. 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.

Answer 2

Closing and reopening Visual Studio 2013 worked for me!

Answer 3

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)!!!!

Answer 4

For me the following steps worked:

• Find the project that is not building
• Remove/add references to projects within the solution.

Answer 5

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).

Answer 6

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...