Found plugins with same names, and . Delete the one of the duplicate plugins.

Error: Found plugins with same names, and . Delete the one of the duplicate plugins.
Error: Plugins colliding with each other.

It's hard to find the plugins when they don't have names.

I get this error after upgrading to Unity 2019.2 from 2018.2. My build for Android does not succeed anymore. It still works for WebGL. This happened on two projects. One happened to work during the following attempts to resolve the issue but I didn't know where

I have removed all the plugins except Unity UI and commented out code related to them.
I switched platforms and attempted to Build. WebGL and PC-Mac-Linux-Standalone work, Android does not.
I changed the scripting backend from Mono to IL2CPP
I tried .NET 4.x and .NET Standard 2.0
Help>Reset Packages to Default

My last resort would be to remake the project as a new Unity Project.

What can I try before remaking the project?

 

After trying more things I seem to have fixed the issue by reopening the project in 2018.2 and letting Unity convert it back then opening it again in 2019.2 and letting Unity convert it again.

 

same error with unidentified plugins. this solution worked for me also.

 

Thanks a lot for your idea, so simple. I don't know why is didn't think of trying that.

 

It Worked thanks bro.

 

I just "Reimport All" assets and it helped.