Unable to build for android with facebook sdk and google play together in Unity 5.3.4

Question

I am using facebook-unity-sdk-7.3.0 and GooglePlayGamesPlugin-0.9.32 in my project. it does not let me build for android and fails with error \'Unable to convert classes

Answer 1

'Unable to convert classes into dex format. See the Console for details.'.

this one shows up when a class/dll exists twice in the project.

Often it happens when updating framework, if you do not remove the old version properly, then some classes may appear twice.

Since they are stored in plugins folder, Unity does not check them and they only show up in build process.

Best could be to remove everything related to both plugins and reimport them. That solved it for me when using UniWebView and Vuforia in same app. One of those was not properly updated.