Every second time I open visual studio, after selecting my php solution, before the main (fullscreen) window opens, I get the "project is being loaded" progress bar. This bar will stay indefinitely (I've let it run over 8 hours) and VS goes inactive. When I force-kill the process and load visual studio again, it will say "Error while last loading of this solution while opening associated documents. The loading of documents will be skipped, in order to prevent this error." (Translated from German). And indeed, all my opened documents are gone. It has been happening for a few revisions of php tools now.