A while back I began developing a solution in FM12. As it matured, I convinced my school to purchase FM 13 and tookover the development in that. I've been working on it for a few months in FM13; Meanwhile, my laptop at home still has FM 12 on it. Today I tried to open the solution on my laptop and got an error that the file was made in FM 13 and cannot be opened in FM12. But I'm almost positive that I opened the solution in FM12 on the laptop a few weeks ago. Now FM12 won't open it. The file, of course, still has a .fmp12 extension. Is there some feature thatI've incorporated into the file that's causing this? I'll be really pissed off if FM forces me to buy FM 13 copies for my laptop just to continue to work on this. If I had known I would have kept it in 12. I'm not using any features that 12 doesn't have. Any thoughts?