Welcome to the forum.
Unfortunately, PrE does not offer that many options, if a Project goes "off."
However, these would be my first steps, and pretty much in this order:
- Go to the PrE AutoSaves, and change the View to Details, so you can see the Dates/Times. Try Opening the very latest one. Note: if you have not changed the default, there should be five AutoSave files, and they should be located in the PrE AutoSave folder, in the Project's heirarchy. You want the latest one, not the one with the highest increment. AutoSave 03 could be newer, than AutoSave 05.
- If that does not work, then try this - Move your Assets to a new location. Then, Open your original Project. As it loads, you should be presented with "Where is file _____?" and that is what you want.Here is the tricky part. If you have many Assets, and hopefully they are in the same folder, or a few folders, and not spread around the system. I would move all Video Assets to a Video folder, all stills to a Stills folder, all Audio to an Audio folder, etc. as you want to isolate things. When presented with the "Where is file ____?" navigate to the folder with that file, and locate it. PrE will then relink to all used Assets in that folder. This is why I would segregate Assets by type, to isolate the problem, if possible. If all of your Video files load fine, you will get a "Where is file ____?" for the stills, or the music, and repeat. If the Project fails on one Asset type, then you have located the bad Asset by type, and can repeat the exercise, by segregating each file in that Asset type, to a unique folder, navigating to each folder, when prompted, until you find the bad Asset.
In the tests above, never do a Save, but only a Save_As, so as to not overwrite the original PREL file.
Good luck, and hope that it is a bad Asset, and nothing more.
If you still want to troubleshoot this after working through Bill's advice, you can provide us with more information:
What operating system are you using? Have you manually gone to Windows Update and ensured you have even the non-critical updates?
How fast is your processor and how much RAM do you have? How much free, defragmented space is on your C drive?(You'll need at least 30 gigs -- and it needs to be cleaned and defragmented regularly.)
Are you video files located on your C drive or on a second or external drive? Have you ensured that this drive is formatted NTFS and FAT32 (as drives come from the factory)?
What type of camcorder is your video coming from and how did you get it into your computer?