the main scene of the project builds now, but I still can't enable the IK plugins.
I also received 13 errors that look kinda like this:
E 0:00:01.439 can_instance: Cannot instance script because the project assembly is not loaded. Script: 'res://addons/TwistedIK2/IK_3D/Twisted_ModifierDuoIK3D.cs'.
<C++ Error> Method failed. Returning: __null
<C++ Source> modules/mono/csharp_script.cpp:2902 @ can_instance()