The cause of this error is the client's data file; SQL Loader is expecting to load positions (based on the Control file) that are not present.

For example, the Control file will be expecting to load through positions 6800, but the client's file ends at position 2500.

This message will appear on the UL_ACCOUNT_MESSAGES table by PROCESS_ID, as well on the Upload Account Reconciliation screen on the front end of Team Approach:

User-added image

To resolve, the client just needs to reformat the file.