To me, this error comes from your code. Please check the clipboard page:newAssignPage of this WO and see the property:pxFlowName has value or blank.Also, check if Param.flowName is set anywhere in your code. Please open the logs for this WO and see any clue. Also,check the tracer while opening this errored WO. I hope you will get some clue with these troubleshooting and is not related to V62 I guess.