You may have already looked at the following... KB23954-"App Error 606" is displayed on the BlackBerry smartphone
If you haven't already, try a hard reset.
If that doesn't fix it, try rebooting in safe mode. KB17877-How to start a BlackBerry smartphone in safe mode
If you can reboot in safe mode, then you should be able to do a backup using Desktop Manager.
If you end up having to wipe the device and reinstall the OS and you have no backup, then your data is gone. Posted via BlackBerryForums.com Mobile