I cannot open LR4. I get an, "Unexpected error opening catalog. The catalog could not be opened due to an unexpected error." What's up with this? So, what's the error, how do I fix it? This morning, after an auto update from Microsoft, I had problems booting up. Got back up, but had to revert to an earlier version, 23 June. I didn't think the revert would push LR4 to 23 June (that's what properties says). The catalog is for 24 June. Could this be the problem, and if so, how do I resync the catalog to the program? Otherwise, how do I recover without loosing all my book work?