Weird error I've never seen before using the latest nightly build

Hi, I’ve been using both stable 3.0 SDK and edge nightly builds for some time now and I came upon a very weird error today. I left the project open and computer unattended for a long period of time and when I came back and ran the project, it ran for a couple seconds and then it threw this at my face! O.o

Any idea? I’ll try and restart my computer…