Extend job offer throw many erros JBO-29000 and IRC-1590777

Summary:

each time our recruiter tries to extend job offer, they have those errors

JBO-29000: Unexpected exception caught: java.lang.NullPointerException, msg=null

There was a problem with the job offer letter.IRC-1590777 This job offer can't be extended because the job offer letter wasn't created by the BI Publisher server

after trying 5 to 10 times, the error disappears

Content (required):

when creating job offer, the recruiter download the offer letter

they modify it by adding some texts, they save it and upload it

they extend it and then errors is encountered

21D