07-08-2013 07:24 AM - edited 07-08-2013 07:26 AM
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To reinstall your BBM and BlackBerry World applications the BlackBerry Menu key would be required. To attempt to resolve the issue with your Menu key I would suggest backing up and doing a clean reload of the BlackBerry device software as shown here: http://btsc.webapps.blackberry.com/btsc/KB11320. Please test before restoring any data to the device.
If this resolves the issue do a selective restore of essential data (Address Book, Calendar, Task, Memos, BBM contacts etc.)
How to use BlackBerry Desktop Software to restore data to a BlackBerry smartphone from a backup file
If the issue still persists after the reload, further investigation might be required. To help further diagnose the cause, contact your wireless service provider or BlackBerry Technical Support Services for further review and support.