Hey Guys,
we are using a lot of dll’s in the development of our applications. In order to debug those, Unity needs to have mdb files. The old behaviour was, that as soon as you enter the playmode the mdb files get generated. With 2019.3 this is not working any more.
Is this a intended changed?
Since 2019.2, the new scripting runtime is the only option. The new scripting runtime can handle mdb files or portable pdb files (still extension pdb). If you are generating portable pdb files then debugging should work as expected.
I just noticed this thread when I was looking to solve a similar problem. This might not have anything to do with your problem but I figured I would share what helped me solve my issue. Also note that I am using Unity 2019.2.6f1 and visual studio 2019.
We are also using dlls in our project and since we updated from VS2017 to VS2019 we have not been able to “step into” our dll source code. The solution I found was to generate a portable pdb, like mentioned above, which was not done automatically for us. In order to generate a portable pdb you have to change the property in your dlls .csproj file from full to portable (portable). After doing this I just had to add the .dll and .pdb files to the Asset\Plugins folder and I was able to step into and set breakpoints in the dll source code.
Hope this helps.