You know it is CA Pin Error if the message says as followed:
Prior Year AGI [PriorYearAGI] in the Primaryor Spouse/RDP Signature [SpouseRDPSignature] element does not match FTB’s records, therefore you cannot sign your return electronically. You can still e-file by signing Form 8453-OL.
Solution: Log-in to your account. Edit your CA return. Click Self-Select Pin TAB. Move your option to "Check here if you WANT to E-FILE using Form 8453-OL as your signature.". Save your answer then save and continue through the software to re-submit your return(s).