Error "Internal error occurs during export of vcenter server common upgrade component" While upgrading windows vCenter

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• Windows vCenter Upgrade from 6.0 U3 to 6.5 U2,  Failed with error "Internal error occurs during export of vcenter server common upgrade component"
• The logs contains the following errors.

upgrade runner.log
2019-06-22T07:18:11.148Z ERROR upgrade.states.component_states common_upgrade:Export: Remote script failed with an error [InternalError()]
2019-06-22T07:18:11.150Z ERROR upgrade.states.component_states common_upgrade:Export: failed with internal error. For details take a look at Export_com.vmware.common_upgrade_2019_06_22_12_48.log.
2019-06-22T07:18:11.157Z WARNING wf.wf_processor State Export com.vmware.common_upgrade has failed.
2019-06-22T07:18:11.157Z ERROR wf.wf_processor Workflow execution has failed
Export_com.vmware.common_upgrade_2019_06_22_12_48.log:
2019-06-22T12:59:19.819Z ERROR __main__ Upgrade Phase 'common_upgrade:Export' failed. Exception: [Errno 13] Permission denied: 'C:\\Windows\\system32\\drivers\\etc\\hosts'
Traceback (most recent call last):
  File "C:\vcs3249.tmp\PFiles\VMware\CIS\cis_upgrade_runner\payload\componentPhaseLauncher.py", line 438, in main
    executionResult = systemExtension(exeContext)
  File "C:\vcs3249.tmp\PFiles\VMware\CIS\cis_upgrade_runner\libs\sdk\extensions.py", line 94, in __call__
    result = self.extension(*args)
  File "C:\vcs3249.tmp\PFiles\VMware\CIS\cis_upgrade_runner\libs\sdk\extensions.py", line 110, in _func
    return func(*args)
  File "C:\vcs3249.tmp\PFiles\VMware\CIS\cis_upgrade_runner\payload\component-scripts\common_upgrade\__init__.py", line 41, in exportData
    exportHostsFile(exportDir)
  File "C:\vcs3249.tmp\PFiles\VMware\CIS\cis_upgrade_runner\libs\sdk\persist_hosts_file.py", line 54, in exportHostsFile
    shutil.copy(sourceHostsFile, exportHostsFilePath)
  File "C:\vcs3249.tmp\PFiles\VMware\CIS\python\lib\shutil.py", line 133, in copy
    copyfile(src, dst)
  File "C:\vcs3249.tmp\PFiles\VMware\CIS\python\lib\shutil.py", line 96, in copyfile
    with open(src, 'rb') as fsrc:
IOError: [Errno 13] Permission denied: 'C:\\Windows\\system32\\drivers\\etc\\hosts'

Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment. 

• You may experience the same error even though the user account  has local admin rights to windows machine  
• This KB is applicable only for windows based vCenter server

Environment

VMware vCenter Server 6.5.x
VMware vCenter Server 6.0.x

Cause

The upgrade process unable to access the information from hosts file, C:\\Windows\\system32\\drivers\\etc\\hosts file  is locked.

Resolution

• Issue can be resolved by changing the hosts file permissions
• Grant full permission to user who logged in to the Windows vCenter machine