UEFN Editor Stuck opening project

I won’t be able to ask him till we’re back in the office on Tuesday, but a bit more info. If I go back to a previous revision that I could open, before he added anything to the project, it still hangs on open. The only changes in the project at that point should be ones I have added myself.

Does this sound right? Is there any workaround I can do to get it to open before the update is pushed?