06-04-2010 01:11 PM
Are you using the browser on the device to go to the website and you're getting that error message?
The other two ways are to try looking for it in App World and downloading it.
Or you can download the OS for your phone from the link below. Once the Desktop Manager and Device software is installed, you can go through the Application Loader and reinstall the OS and place a check mark next to BlackBerry Messenger to install it again.