EOUFDATACONV app engine - HR9.0 to HR9.1 upgrade

We're in process app upgrade from HR9.0 to HR9.1. The data converstion failed multiple times and after fixing the issue we restarted the data conv and it processed the same process instance and failed at diffrent step after 5 days of debugging when i restarted the data conv it  is not picking the existing process instance instead it created the new peocess instance and trying to run and it failes saying that "all process failed: restart Oprid =PS, Runid=HC90_2 , PI=175525 (this is old process instaance) and when i checked all the state records associated to the UPG appengines where