I believe REJ001 refers to a state return being rejected because there was an error with the federal return.  Since this has to do with an incorrect SSN of your client, you may like to follow the instruction in the article below to correct the error and resubmit the returns.  Based on your question, however, it appears that PTO has locked the cell for SSN for changes, which is unusual.  Is that what's happening?

https://accountants-community.intuit.com/articles/1607179-resolving-e-file-rejection-0500-primary-ta...