I have been working in a development environment with 7.x-2.1 for the past two months. Upon a fresh install, navigating to admin/config/group/group-views and saving worked fine. But after several weeks, when re-checking the settings and clicking on admin/config/group/group-views, I get the following error:

Fatal error: Unsupported operand types in /htdocs/modules/system/system.module on line 2128

I tried upgrading to 7.x-2.2 to see if that would resolve the error, but I'm still getting it.

I also get this error when navigating to /admin/config/group