Unity plugins colliding with eacother error message when I build and run

Every time I try to build and run any of my projects, I keep getting the same error message. I tried reimporting all assests, creating new project and importing all assets, and I even tried redownloading Unity. I am running 5.2.1p4. None of these attempts fixed my issue. I am out of ideas, and cannot build any projects! Here is the error message that I keep getting:

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/Scenes/TestBuild_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/Scenes/TestBuild_Data/Managed/UnityEngine.Networking.dll would be copied to /UnityEngine.Networking.dll Please fix plugin settings and try again.

UnityEditor.Modules.DefaultPluginImporterExtension:CheckFileCollisions(String) UnityEditorInternal.PluginsHelper:CheckFileCollisions(BuildTarget) (at C:/buildslave/unity/build/Editor/Mono/Plugins/PluginsHelper.cs:25) UnityEditor.HostView:OnGUI()

Plugins colliding with each other

Any ideas about how I can fix this?