Problem: When VMware vCenter Converter Standalone tries to connect the source vCenter (5.5), after enter the Destination System details and click ‘Next’, an error show:
A general system error occurred: SSL Exception: error:14077102:SSL routines:SSL23_GET_SERVER_HELLO:unsupported protocol
Solution: By default, VMware vCenter Converter Standalone 5.x and 6.0 default the converter worker encrypts the data stream using SSL. Encrypting the traffic increases security, but it can decrease performance. For ESX 5.5 or older version that need TLS 1.0.
Option 1: Follow below steps to disable SSL encryption in VMware vCenter Converter Standalone 5.x and 6.0.
Step 1: Take a backup of the converter-worker.xml file. By default, this file is located at:
Windows 7/Server 2008 and Later – C:\ProgramData\VMware\VMware vCenter Converter Standalone
Window Vista, XP and 2003 Server - %ALLUSERSPROFILE%\VMware\VMware vCenter Converter Standalone
In older Windows versions – %ALLUSERSPROFILE%\Application Data\VMware\VMware vCenter Converter Standalone
Step 2: Open the converter-worker.xml file using a text editor.
Step 3: Locate the tag pair <useSsl></useSsl>. It is located inside the <nfc> tag and has a value of true.
Step 4: Change the value to false.
Step 5: Save and close the file.
Step 6: Restart the VMware vCenter Converter Standalone Worker service on the machine.
Option 2: Due to TLS1.0 disablement in new versions but not in vCenter 5.5. As workaround you can enable TLS1.0 in converter-server.xml, converter-worker.xml and converter-agent.xml by changing tag from 123422720 to 56313856 and then restart services. put the same option in converter-client.xml placed in installation folder.
converter-client.xml: %ProgramFiles(x86)%\VMware\VMware vCenter Converter Standalone\converter-client.xml
Option 3: If still not working the best way is to upgrade 5.5 to latest available.
Reference: VMware Knowledge Base: Disabling SSL encryption on VMware Converter Standalone 5.x and 6.0 (2020517)