[brianogilvie]

If I were you, I would open the ~/Library/Application Support/OmniFocus directory (~ means your home directory) and option-drag the OmniFocus.ofocus package to the desktop, so you have a copy of the database's current state.

I would then try the Rebuild Database... command from the File menu.

If that didn't work, I would restore from my most recent backup. In any case, my next step after that would be to email Omni (with Help*> Send Feedback...) to let them know about the problem, and attach the OmniFocus.ofocus package that I dragged to the desktop.

Good luck!