AAM crashes in one user, works in the other...

I have a ton of CS applications installed on my Mac, and switch between several users, depending on my activity (researching, presenting, teaching). Until last week, everything went fine: all CS6 applications ran under CC, even CCC seemed up to date and all apps reported nicely in my AAM (apart from those AIR-based apps). Until Muse prompted me to update, which I did. AAM downloaded Muse, installed it, and I opened it. Muse prompted me to supply more CC account details, but as I did that, it said there was an unexpeted error (I-200). I tried again, but in vain - the same message. I didn't have time to look into the problem immediately, so I left it for a while.

A few days a casual system restart passed by, and I noticed more CC problems: CCC didn't sign in anymore, and AAM crashed, as soon as I was prompted to sign in. I hoped that after removing the previous version of Muse, things might change for the better, but it didn't. AAM still went on crashing and Muse kept throwing that error. I tried replacing AAM with a manually and freshly downloaded and installed version. But still, exactly the same trouble.

Strangely enough, on another user (on the same Mac), AAM, CCC and Muse run just fine ! I was even able to install the Muse update, with some difficulties though, but I don't think these were directly related to the above problem. AAM reported a "beta version present", which is just not true. So I manually ran the Muse installer, with no problem. Still, AAM is not satisfied and keeps telling me it can't install Muse, due to that resident beta version. Whatever...

Well, a couple of weeks ago, someone at a different forum advised users to delete a certain AAM prefs storage folder from the User Library. And it helped in some cases and circumstances ! I wonder if I could give that a try, but I've forgotten the name of that folder and can't retrieve the forum post anymore.

Any clues, advice, or solution ?