An update to BlackBerry Maps was released just a few days ago that was supposed to fix the app as far as upgrades, stability and performance. While many users downloaded the update and are running BlackBerry Maps with no issues, just as many seem to be experiencing problems with the app now. Reports are flying in that Maps has gone down the tube and won't even start for some users.
Thankfully forums member fbf2012 has come to the rescue and posted a workaround for those that are having issues. The process involves heading to BlackBerry World from a PC and installing BlackBerry Maps, however this method should push an older (working) version to your device instead of the new "updated" version.
So if you're having issues, swing by the forums and give it a shot. You'll need a Windows PC to do it but it looks like it has been working for most users. Be sure to leave a comment letting us know if it worked for you.