Error attempting Backup PBM

I am getting this error

"Error attempting Backup PBM

Please check InvSvc upgrade logs for details."

while trying to upgrade my vCenter 5.5 to 6.0

I tried VMware KB: Resetting the VMware vCenter Server 5.x Inventory Service database . But I was getting errors at the end. The error number was '8'  and '8' instead of 2x '8'.

2015-04-21 20:29:16.132+03:00| vcsInstUtil-2562624| I: Entering function: ParseStatusFile

2015-04-21 20:29:16.133+03:00| vcsInstUtil-2562624| I: ParseStatusFile: curr error msg: "Error attempting Backup PBM"

2015-04-21 20:29:16.133+03:00| vcsInstUtil-2562624| E: ParseStatusFile: Displaying error message for " ": "Error attempting Backup PBM

Please check InvSvc upgrade logs for details."

2015-04-21 20:29:50.017+03:00| vcsInstUtil-2562624| I: Entering function: ShowMessageQueue

2015-04-21 20:29:50.017+03:00| vcsInstUtil-2562624| I: Leaving function: ShowMessageQueue

2015-04-21 20:29:50.017+03:00| vcsInstUtil-2562624| I: Entering function: ShowMessageQueue

2015-04-21 20:29:50.017+03:00| vcsInstUtil-2562624| I: Leaving function: ShowMessageQueue

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| I: ParseStatusFile: got error or success

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| I: ParseStatusFile: keeping completed status file: C:\Users\SPARKS~1\AppData\Local\Temp\UpgradeRunnerExportOutput.json

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| I: Leaving function: ParseStatusFile

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| I: MonitorStatusFile: Parse callback gave final result: 0

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| I: MonitorStatusFile: called parse callback 5 times

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| I: MonitorStatusFile: No need to wait for process to complete

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| I: MonitorStatusFile: Process's job tree still hasn't terminated, waiting

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| I: MonitorStatusFile: Wait on process's job tree has completed: 0

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| I: Leaving function: MonitorStatusFile

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| E: LaunchProcAndMonitorStatus: Failure detected while monitoring status file

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| E: LaunchProcAndMonitorStatus: Job still alive, terminating

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| I: Leaving function: LaunchProcAndMonitorStatus

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| I: Leaving function: LaunchProcAndMonitorCommonStatusFile

2015-04-21 20:29:50.018+03:00| vcsInstUtil-2562624| E: LaunchUpgradeRunnerCommon: Failed to run import/export phase: "Z:\PFiles\VMware\CIS\python\python.exe" "Z:\PFiles\VMware\CIS\cis_upgrade_runner\UpgradeRunner.py" --mode=export --configFile="C:\Users\SPARKS~1\AppData\Local\Temp\UpgradeRunnerInput.json" --logDir="C:\Users\SPARKS~1\AppData\Local\Temp\vcsUpgrade" --locale=en --outputFile="C:\Users\SPARKS~1\AppData\Local\Temp\UpgradeRunnerExportOutput.json"

Could someone please help?

Thanks in advance.