If the General Ledger run only produces PDF and text files, even though the user has pay group access, the issue is due to the missing .CSV file extension in the file association for the pay group.
To resolve this, follow these steps in Back Office:
Click CorePay then click Reference.
Click Advanced Reference Features then click Reference D-J.
Click GL Parameters then click File Association.
In the File Name column, add the .CSV file extension at the end of the file name.
Re-generate the General Ledger.
The CSV file should now generate as expected.