"Expecting property name enclosed in double quotes", vCenter Server Convergence using CLI method fails during PrecheckVcTask

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• You are trying to converge vCenter Server using CLI method
• Convergence fails during Pre-check phase, you will see entries similar to below in vcsa-converge-cli.log:

2019-06-15 17:20:09,713 [loggable.py:102]: PrecheckVcTask: Caught exception Traceback (most recent call last):
  File "d:\build\ob\bora-12665614\bora\install\vcsa-installer\vcsaConvergeCli\cli_tasks\converge\precheck_vc_task.py", line 115, in execute
  File "d:\build\ob\bora-12665614\bora\install\vcsa-installer\vcsaConvergeCli\cli_tasks\converge\precheck_vc_task.py", line 179, in do_version_precheck
  File "D:/build/toolchain\win32\python-3.5.2-openssl-1.0.2q-vc140\Lib\json\__init__.py", line 319, in loads
  File "D:/build/toolchain\win32\python-3.5.2-openssl-1.0.2q-vc140\Lib\json\decoder.py", line 339, in decode
  File "D:/build/toolchain\win32\python-3.5.2-openssl-1.0.2q-vc140\Lib\json\decoder.py", line 355, in raw_decode
json.decoder.JSONDecodeError: Expecting property name enclosed in double quotes: line 2 column 1 (char 36)

2019-06-15 17:20:09,739 [loggable.py:102]: ================ [FAILED] Task: PrecheckVcTask: Running PrecheckVcTask execution failed at 17:20:09 ================
2019-06-15 17:20:09,740 [loggable.py:102]: Task 'PrecheckVcTask: Running PrecheckVcTask' execution failed because [Expecting property name enclosed in double quotes: line 2 column 1 (char 36)], possible resolution is [Refer to the log for details]

Environment

VMware vCenter Server Appliance 6.5.x

Cause

This issue is observed if Converge CLI Utility (vcsa-util) from an incorrect vCenter build is used. For example, vCenter is running with version 6.5 and vcsa-util from vCenter Server 6.7 ISO is used to Converge.

Resolution

• Identify the Build Number of vCenter Server, refer to Determining the build number of VMware ESX/ESXi and VMware vCenter Server and Build numbers and versions of VMware vCenter Server
• Download the ISO of same version and retry the convergence using vcsa-util available at vcsa-converge-cli directory in ISO

Additional Information

Understanding the vCenter Server Converge Tool
Syntax of the Converge Command