Migration pre check fails,Internal error occurs during VMware vCenter Inventory Service pre-upgrade checks

 Symptoms

When migrating the vcenter from 6.5 to 6.7 ,the pre checks fails with error

migration-assistant-16046470| I: ParseErrorsWarningsFromPreUpgradeOutput: Error messages: Error: Internal error occurs during VMware vCenter Inventory Service pre-upgrade checks.

In the collection requirement logs for invsvc:

2020-07-08T10:57:23.144Z INFO service_manager Parsing service status The specified service does not exist as an installed service.^M
2020-07-08T10:57:23.144Z ERROR __main__ Upgrade Phase 'is:CollectRequirements' failed. Exception: Service 'vpxd-svcs' does not exist.^M
Traceback (most recent call last):^M
  File "C:\mig156A.tmp\PFiles\VMware\CIS\cis_upgrade_runner\payload\componentPhaseLauncher.py", line 461, in main^M
    executionResult = systemExtension(exeContext)^M
  File "C:\mig156A.tmp\PFiles\VMware\CIS\cis_upgrade_runner\libs\sdk\extensions.py", line 94, in __call__^M
    result = self.extension(*args)^M
  File "C:\mig156A.tmp\PFiles\VMware\CIS\cis_upgrade_runner\libs\sdk\extensions.py", line 110, in _func^M
    return func(*args)^M
  File "C:\mig156A.tmp\PFiles\VMware\CIS\cis_upgrade_runner\payload\component-scripts\is\__init__.py", line 61, in doCollectRequirements^M
    return is_upgrade.collectRequirements(context)^M
  File "C:\mig156A.tmp\PFiles\VMware\CIS\cis_upgrade_runner\libs\sdk\extensions.py", line 110, in _func^M
    return func(*args)^M
  File "C:\mig156A.tmp\PFiles\VMware\CIS\cis_upgrade_runner\payload\component-scripts\is\is_upgrade_600.py", line 145, in collectRequirements^M
    isStatus = serviceManager.getStatus(isserviceName)^M
  File "C:\mig156A.tmp\PFiles\VMware\CIS\cis_upgrade_runner\libs\sdk\service_manager.py", line 979, in wrapper^M
    return getattr(controller, attr)(*args, **kwargs)^M
  File "C:\mig156A.tmp\PFiles\VMware\CIS\cis_upgrade_runner\libs\sdk\service_manager.py", line 812, in getStatus^M
    status = self.__getStatus(serviceName, statusParser or self.statusParser)^M
  File "C:\mig156A.tmp\PFiles\VMware\CIS\cis_upgrade_runner\libs\sdk\service_manager.py", line 693, in __getStatus^M
    status = statusParser.parse(cmdResult, serviceName)^M
  File "C:\mig156A.tmp\PFiles\VMware\CIS\cis_upgrade_runner\libs\sdk\service_manager.py", line 245, in parse^M
    raise IllegalServiceError("Service '%s' does not exist." % (serviceName))^M
IllegalServiceError: Service 'vpxd-svcs' does not exist.^M

Cause

This happens in case the service-control file on the source vcenter machine is corrupt or blank

If you run the service-control command it will either give a traceback or no output at all

Impact / Risks

pre checks fails stating IllegalServiceError: Service 'vpxd-svcs' does not exist.

Resolution

Replace the service-control file from a working environment (lab) on the source vCenter
Test if the service-control --status --all gives expected output

Re run the migration assistant