When trying to launch Touchdown for iOS or Android, it fails with an an error about a Corrupt database.
The recommended fix is to uninstall then reinstall TouchDown (not your license key program Exchange by Touchdown key, but the free trial version of Touchdown for Not so Smartphones or Touchdown for Smartphones, or Touchdown HD , depending on how new your device is and the OS version). If you leave your key installed, it should recognize any new version of TouchDown that you install onto the device.
If you are reinstalling the exact same product you uninstalled (Touchdown for Smartphones or Touchdown HD) you can use the Backup settings function in Touchdown settings>advanced>legacy settings screen>advanced>backup settings to backup most settings. Rules and Peak times are not included. Once you reinstall and configure, select Restore settings in Touchdown settings>advanced>legacy settings screen>advanced.