I have the exact same thing happening right now. Super frustrating.
[Don't think this is the reason BUT...] The only thing I can think of is that I used a database browser (SQL lite) to rummage through the hidden db files in the GMATPrep software (trying to find my AWA essay from the first practice test). This was a read only process and I copied all the files that weren't encrypted to a totally different directory before browsing so there was no editing or screwing with the content of those files.
My test is this Monday and I'm trying to get my last practice and review in before cooling off for the weekend. I'll update if I see the same continuing into the quant and verbal sections. Fingers crossed. If it does look to be the same test I may copy my results from last weeks test (Gmat prep practice test 1) to a temp directory and reinstall the software. Again, I'll update if I have to do that and whether it's a solution.
PS- My attempt to find the AWA failed miserably. Seems to vanish into the ether once you finish it. Very frustrating for those like me who shell out booku amounts of money for Kaplan or like programs that feature essay grading. Thankfully I haven't heard many programs looking heavily at the essay compared to a flare of adcom's saying they're now looking at the IR more than in past years.