Moved to Premiere Pro forum.
Try importing the troublesome project into a new project and saving it with the new name. It looks like the current project is corrupt.
I have tried that a few times, Ive tried both importing and copying but it still brings up the errors (allbeit with about 30 seconds more tolerance!) The most recent thing I've found is that it brings up about 6-8 of those serious error messages but once I close them it still lets me use the project. It just scrambles the timeline so I can't do anything to it. So frustrating that I can see everything but can't do anything to it!
Try launching Pr from a desktop, task bar or start menu icon while you
hold down the Shift+Alt keys. Keep them pressed until you see the Pr
welcome screen. Alt resets your preferences and Shift clears out the