Library can't be repaired or rebuilt

I have a 20GB aperture library on an external server. I tried to open it today (Aperture is updated to the most recent version), and it said that the library needed to be repaired. The progress window popped up, but after a minute Aperture mysteriously quit with no explanation or error. I have tried both repairing and rebuilding, but the same thing happens either way. I was able to repair permissions but still have the same problem with repairing or rebuilding after that. These same issues happen if I try to open the library in iphoto too. Any ideas? It wouldn't be too hard to start a new library from scratch and organize, but I'd hate to lose all my tags.