I’m also getting this (in 5.1.1). Our team uses Plastic SCM for source control and I hit this crash when I click to Browse and open the project. Our project was last saved in an older version of the editor and I re-opened it using “Open a copy” previously, then closed the project (without saving any changes). It is when I re-open the editor and click “Browse” to open the project that it crashes immediately. I don’t even get to try to open the project. If I delete all untracked/uncontrolled files, i.e. files not tracked by source control, then open the editor and click Browse, I can browse and open the project again.