The crash occurs when I change a filesystem link that is pointing to several source directories (e.g. a new version of library source code). VS doesn't seem to be able to handle the fact that the project files have changed. I can work around by deleting the project file, removing the project reference from the vpw file, removing the vpwhistu file (out of superstition). Then, VS will invoke OK and I can re-create the project and load the files back into it. The language I'm using is SystemVerilog.