There are those of us who clear that cache file before we start up (or after we quit, which is the same thing) every time. And, in fact, there are those of us who clear all five of the top level caches even if we aren't adding/removing mods or other content. Probably overkill, but at least one of the mods here (Woohooer KamaSimtra) is known to malfunction for some players when the scriptCache in particular is stale.

Have still never heard of stale caches interfering with EP loading until now, but if that's all it takes to fix things then so be it.

igazor, haha I'm one of those chronic cache deleters! Maybe not *every* time, but every second or third game session. Which is why I'm surprised at that I might not have deleted the scriptCache.package file, because from what I've read, deleting that one is necessary when installing new mods.

Anyway, just another update: In addition to installing SP Careers V268, I also installed HomeOpener. After launching my game without problems and playing for a few (real time) hours last night, I encountered a glitch. Not only could I not open other homes, but I couldn't even open my active household's home. I'm thinking it was a HomeOpener related issue. So I shut down, rebooted, and lo and behold, it began loading without EPs - again. So I shut down, deleted the scriptCache.package file, restarted, and then it loaded just fine, and game play seemed fine too (I didn't play for too much longer after that though).

I dunno exactly what's going on here, but I'm thinking there could be a corrupt file somewhere. If either issue occurs again, I'll try your second suggestion and generate a fresh Sims 3 folder.