Same issue with Blueprint Assist.
Windows, UE5.5.
LogOnline: Warning: OSS: Invalid response. CorrId=UE4-993b18fa41123efff81667851abe99f6-573B91B4492E22D07A0069B38F39DD5C-466FCB4F416BFAFCB1620389147FF781 code=404 errorcode=JsonErrorUnknownCode errormessage=Server error of type JsonErrorUnknownCode errorraw={“Not Found”:“Could not find any manifest download info with artifactId=Blueprin5dd30dcb4d35V14”}