The error is caused when an XPA ledger has not been selected to import into the Collection. The Endpoint connection path must also have the correct ledger displayed in the field.
To select the ledger:
Go to General Ledger Transactions and select your Collection Period.
Click on Endpoint Type and select either a General Ledger or a Trial Balance import. (XPA-GL, XPA-TB)
Go to XPA File Selection screen, click Select on the XPA file.
The XPA file will be assigned to the collection for the import to be completed.