Error Generating Batch of Confirmation Statements with BAS_CONFSTMT?

When running the process (BAS_CONFSTMT) to generate Confirmation Statements, we periodically receive the following error message, which causes the process to go to No Success:

File: C:\PT860P08B_2308160500-retail\peopletools\src\psmgr\mgrgensql.cppSQL error. Stmt #: 2161 Error Position: 0 Return: 12582 - ORA-12582: TNS:invalid operation
Failed SQL stmt: SELECT DATACHUNK, CHUNKSEQUENCE, CHUNKSIZE FROM PSFILEDATA WHERE FILEID = :1 ORDER BY CHUNKSEQUENCE

Error committing work. The host environment could not complete the CommitWork() function. (2,712) BAS_STATEMENT.PrintConfirmation.OnExecute Name:GenerateStatement PCPC:15599 Statement:216

We do have the output (Confirmation Statement) written to PDF file, which is saved on a server, that is then picked up and emailed to the employee through this same process.