This error can be caused by the following:

1. when updating data, you are attempting to update from too old of a version.

Solution:

You'll need to get an older full update to update to first, and then update the data to the latest version.

2. After updating to a newer version of the program you get this error when logging in.

Solution:

You updated an older version of the program from a patch instead of a full install and are missing the updated DB.DLL file as well as several report files. Uninstall the program from this workstation and reinstall using the full update and then patch it to the latest version. The full update and patch must be from the same major version of the program. For example  a full update 2860 and patch 2869 would work, but a full 2779 and patch 2869 would result in the error.