BI_WRKSHTUPD (billing worksheet approve later batch update) abended
Below is a snapshot of the message log.
It appears the process may have locked all the temporary invoices due to the failure. The TMPs cannot be found on the BI_HDR and BI_LINE tables. I am able to see them online under the "Bills Not Invoiced" however, when I click on the TMP link, i cannot access the header (no matching values found). I researched the error on Oracle support and was able to find Bug 29133325, available in PUM 31. I tried to replicate the issue by invoicing from three contract lines with different Bill By Id. I was unsuccessful as the process (bi_wrkshtupd) ran to success each time.