Yes, I have tons of custom content. But when corrupted saves first started happening, I didn't have anything, it was just the base game and some expansions, and I always have different cc installed when the save corrupts.
I've since re-installed the Sims 3 and the expansions several times over, but I still get the problem. I use The Sims 3 Crash Log Analyzer to determine the problem, which is corrupt saves. The custom content I have now is all fully updated, and either from nraas or thesimsresource.
I occasionally get error 16 when saving, but it usually only happens once then I'm fine to save again and continue on. Could that be an indicator of a corrupt save?