how do i fix this?!

Questions & Answers
1

i have problem when i try to build the game , here is the problem:Plugin ‘UnityEngine.UI.dll’ is used from several locations:
C:/Program Files/Unity/Editor/Data/UnityExtensions/Unity/GUISystem/UnityEngine.UI.dll would be copied to /UnityEngine.UI.dll
Assets/thefofn_Data/Managed/UnityEngine.UI.dll would be copied to /UnityEngine.UI.dll
Plugin ‘UnityEngine.Networking.dll’ is used from several locations:
C:/Program Files/Unity/Editor/Data/UnityExtensions/Unity/Networking/UnityEngine.Networking.dll would be copied to /UnityEngine.Networking.dll
Assets/thefofn_Data/Managed/UnityEngine.Networking.dll would be copied to /UnityEngine.Networking.dll
Please fix plugin settings and try again.

2

I had the same problem, just delete your library folder and it will be fixed

3

“SoloDeveloper”

Don’t do it, If you delete your library you delete your whole Project !,Let me try it