You may be experiencing any of these issues:

• You receive the error message "Visual Voicemail is Full."
• You are unable to access Visual Voicemail.

Clearing the app's stored data may solve the issue. Follow these steps to clear the app's data:

1. Navigate to Menu > Settings > Applications > Manage Applications.
2. Tap the All tab at the top of the screen.
3. Scroll to and tap the Visual Voicemail application.
4. Tap Clear Data.

Freeing up your phone's internal storage may solve the issue. Follow these steps to check how much storage space you have left on your phone:

1. Navigate to Menu > Settings > Storage.
2. Under Phone storage, view Available space.
   If the internal storage is 25 MB or less, free up internal storage space. See I am running out of storage space on my device and How to expand storage on your device.

NOTE: If you do not wish to use Visual Voicemail, some phones allow you to uninstall it.