I had this exact same problem after loading a trial version of DIY Fitness with the desktop app loader. Not sure why it happened but I followed the link to the latest 8100 software from my service provider and it fixed it.
This forum doesn't allow me to post the URL to the solution yet. So find the link to BlackBerryOS 4.x Download FAQ for yourself and install the software from your own SP.
I have my browser icon back