Originally Posted by aiharkness
Try this. See if BBM shows as an installed app in device options. If so, delete it. Then install BBM using desktop manager. Afterward, go back to app world and upgrade if it shows upgrade available.
Worst case you may need to re-install the OS. If you do, just selectively restore your personal data and not settings. So skip the automatic backup/restore and do a manual backup beforehand.
And don't double post.
I had app world on the brain when I posted this. This happened to me with that app and the above is what I had to do.
The first thing to try is a battery pull, as Dub says. I tend to doubt that is the fix in this case. If so, then the next thing to try is see if BBM shows as installed, delete it, then reinstall from app world.