Using Outlook for Android in business environments for email and scheduling
Seems like they've put it in the too-hard basket.
I've just fixed this issue after being in the same boat for a few weeks: Outlook app worked fine for my work email until change of password. From then it only gives 'an error occurred', while OWA and stock xperia/android email app continue to operate normally with that account.
Followed the suggestions throughout this thread, including uninstalling and reinstalling, playing with account settings and cache but no luck.
Just now it has suddenly worked out of the blue. I went to add an account through settings > accounts > add account > outlook, and after putting in the email it actually went to my organisation's sign-in page, instead of the usual error. I noticed I was connected to my work's wifi when it worked, and i'm usually trying to fix this pesky issue elsewhere.
Perhaps give that a try, in case it helps, though it could have just been random luck..
Hopefully it lasts, either way i'm sure i'll be back here when my password next resets. surely microsoft would have fixed (or at least acknowledged) the bug by then...