34: No Library cache found - ALL assets will be re-imported. 35: + Detected last used Unity version: 2019.2.9f1 36: + Detecting Unity installation ... 37: + Building with Unity installed at /UNITY_PATH/Unity/macos/published/Unity-2019_2_10f1/Unity.app/Contents/MacOS/Unity 38: ! build of 'windows-alpha' failed. undefined method `' for nil:NilClass That is pretty much the extent of the FULL LOG that the build gave which is pretty useless, and gives no clear reason for the failure. One thing that DOES seem odd though is this is supposed to be a WINDOWS build yet unless I'm misreading that log it is using a Mac version of Unity to build? EDIT: I have two build targets one for Mac and one for Windows, and they both failed with no indication of why and they both built using this same MacOs version. I don't know if that last bit is normal or not. My previous builds have mostly all been good so never looked that closely.