Message “Error reading file: TNTCCL.DB Return Code=2” means that the file is damaged. It is an I/O error from Btrieve software which is used to access database files on the Windows platform.
TNTCCL file contains custom code and the reason why export is working for specific program might be because it doesn’t have any custom code in it. Some other program will have problem when exporting if it contains custom code which is read from TNTCCL.
The best way to repair this file is using a backup. If there is no backup, then maybe BUTIL -RECOVER can do something.
Other way to do it is:
BUTIL -CLONE <new_file> <old_file> - creates an empty copy of the old file
BUTIL -COPY <old_file> <new_file> - copy the content to the new file
You can also try if the transport utility works with clean database or with just clean TNTCCL file, to be sure that the corruption is the problem.