Loading symbols for a managed DLL doesn't work in Visual Studio with Unity 5.6.1f1

Unity Engine
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1

I have a managed DLL compiled against the .NET framework version 3.5. Let’s call it plugin.dll.
In my Unity project I have placed it in Assets\Plugins\Win64 and I can use it just fine with the VS project generated by Unity.
I can attach a debugger to the running Unity instance and place breakpoints in all the C# code that belongs to the Unity project, but the symbols for the managed DLL just won’t load.

So, when debugging the project by clicking “Attach to Unity” I can see plugin.dll in the Modules window but the symbols for it don’t get loaded.

I have tried the following things:

  • Turning off Just My Code
  • Placing the generated plugin.pdb file in Assets\Plugins\Win64 next to plugin.dll
  • Adding my VS build directory (with all .pdb’s) to Visual Studio’s Symbol locations list

I’m sure that the .pdb is for the correct version of the library.
If I right click on plugin.dll in the Modules window and choose “Symbol Load information…” no window opens, which is surprising.
If I choose “Load Symbols” from the menu instead, then a modal window with title “Downloading symbols” that says “plugin.dll” gets shown for a few seconds but nothing happens:

I can see plugin.pdb appearing in the symbol cache directory though, so VS seems to find the file.

Specs:
Windows 10 Enterprise 64-bit
Microsoft Visual Studio 2015, Version 14.0.25431.01 Update 3, .NET 4.7.02046
Unity 5.6.1f1 Personal Edition

1 Like
2

I’m having the exakt same issue, running latest VS (2017 15.5.2) and Unity (2017.3). Symbols will not load, selecting load symbols gives no error message but nothing happens.

3

Still a problem in Visual Studio 15.9.6, Visual Studio Tools for Unity 3.9.0.3, and Unity 2018.2.20f1

4

Having the same problem also. Have you guys solved it somehow?

Thanks

5

Any update on this one guys. Having the same problem.

6

Did you build the DLL yourself? DId you make sure that the debug symbol format is “portable PDB”, as opposed to 'Windows PDB"?

2 Likes
7

Yes. It’s my DLL.
Build settings in VS is set as “debugging info = Pdb-only”.
There is no “Windows PDB” option.
But there is a “Portable option”. I’ll try that.

8

That… my friend, totally WORKED!
You were able to provide an info nobody else could have.
Thank you very much.

Debug info setting for pre-compiled DLL in VS project settings must be “PORTABLE”.

As a side note: Exsiting (old) MDB files must be deleted for it to work correctly. Unity still take those old MDBs in effect if they exist.

4 Likes