Try each of the following steps in order until the issue is resolved:
  1. Verify the location of the AddressAccelerator files in User Options is correct. (BB255698) The default location for the April/May AddressAccelerator data files is C:\Program Files\Blackbaud\Postal Tools.
     
  2. Refer to Error: The serial number for your postal CD is either out of date or corrupt / Error: Cannot access address certification dll: when updating or using Address Accelerator (BB91424) for further troubleshooting steps