[QUOTE=JohnnySix]Are references created somewhere in the temp directory while the project is open , that can be deleted by virus/disk cleaning facilities that then could cause either failure or corruption of the file upon attempted saving?[/QUOTE]
Yes. Construct 2, like a lot of software, keeps some files in Temp and cleans them up when you close Construct 2. You must not clean up Temp while Construct 2 is open otherwise it might wipe the files C2 is currently using. Even worse if you open a .capx file the entire project is extracted to Temp, so if you clean up Temp with a .capx open, you'll wipe your entire project off the disk!
I think wiping Temp with any apps open could break a lot of software and not specifically C2. I'll look in to getting C2 to lock those files so other software can't delete it while it's open.