This post will give you an overview of vcenter 6.5 upgrade issue and its troubleshooting steps.
Issues encountered during vCenter 6.0 to 6.5 Upgrade
Issue1:- Invalid Appliance (OS) root password
Description: – While Upgrading PSC appliance we need to provide OS *root* password and it was failing with invalid password.
Resolution1: – Reset PSC OS *root* password through web-console and try again.
- Login to PSC URL <https://PSC_FQDN or IP Address:5480>
- Go to Administration tab
- Change Password
Most Important – I have noticed this issue while upgrading or migrating from vCenter 6.5 U3D to 6.5. For other release i didn’t faced this issue.
Issue2:- VUM Extension blocking Migration
Description: – If VUM Extension is not in use un-register VUM from the vCenter server.
Resolution:- Follow this KB Article https://kb.vmware.com/s/article/1025360
- Power- Off VUM server
Issue3:- Unable to detect Network at Step 8
Description: – If vCenter server Management N/W is configured in Distributed Switch and if we provide ESXi host details at step 3 & 4 we are unable to select N/W option at Step8.
Because, “When ESXi is used as the deployment target, non-ephemeral distributed virtual port groups are not supported and hence, not shown drop-down list.
Resolution:- At Step 3 provide – Target Host details & Select Host, At Step4 provide vCenter server details for Appliance deployment.
Note:- If we provide At setep3 & step4 both vCenter details it will fails to migrate data.

Issue4:- AD users unable to access after PSC upgrade, In disjoint domain namespace the domain users might fail to authenticate after you update to vSphere 6.5
Description:- After PSC 6.0 to 6.5 Upgrade AD users unable to access vCenter server.
Resolution: – Delete the AD account with integrated windows authentication and add again
Note:- To perform below activity requires AD rights.
- Remove PSC’s from AD Object
- Login to PSC <https://PSC_FQDN or IP Address/PSC>
- Login with “[email protected]”
- Go to Appliance Settings –> Manage and Rejoin Server to AD Domain.
- Enterprise AD Domain admin credentials requires from customer.
- Reboot PSC’s.
- Validate vCenter authentication with AD credentials.
Issue 5:- Re-Register VUM with vCenter server
Description:- If VUM extension error triggers then follow this procedure to Re-Register VUM with vCenter server.
Resolution: – Follow below steps
- Login to VUM VM
- Navigate to C:\Program Files (x86)\VMware\Infrastructure\Update Manager
- Find ‘ VMwareUpdateManagerUtility.exe’, double click on it
- Login to the update manager Utility using previously used SSO credentials.
- Navigate to Re-register to vCenter Server –> enter the SSO credentials and new vCenter IP/FQDN and click Apply. This will re-register VUM to newly deployed VC
- Once done, close the wizard, and restart the VMware vSphere update Manager Service
- Login to vCenter and click on plug-ins and enable the VUM plug-in
Issue 6:- Error could not reach the given source vCenter server on “Port 22”
Description: – If SSH is disabled on PSC’s/Appliance vCenter server then this error triggers.
Resolution: – Enable SSH on PSC/Appliance vCenter prior to upgrade.
- Login to PSC/Appliance vCenter through Web with port 5480
- Go to Access
- Click on Edit Option
- Enable SSH

Issue 7 – Windows Migration to 6.5 appliance fails
Description – If source database size is large, then migration pre-check will fail with below error
Resolution – Please check the source database, which table is utilizing more space. Once you find it, either shrink it or compress.
Note – Please refer VMware KB 51589 here.

Issue 8 – Upgrade of vCenter failed with error, “insufficient space on source export partition “/”

Resolution –
- Take a clone or snapshot of source vCenter
- Increase the virtual disk (running on low space), follow below VMware KB https://kb.vmware.com/s/article/2145603
- Followed the article to shrink the source vCenter DB service-control –stop –all
service-control –start vmware-vpostgres
/opt/vmware/vpostgres/current/bin/psql -U postgres -d VCDB
vacuum full;
vacuum analyze;
\q
service-control –start –all - Rebooted the vCenter server appliance and restart upgrad
Issue-9 : vCenter 6.0 migration failing [Error Failed to retrieved remote PSC]
I faced this issue during migration of vCenter 6.0 installed on windows server 2008 R2 to VCSA 6.7u2 with external PSC.
Issue: Error: failed to retrieve version information from remote platform service controller.

Cause: Transport Layer Security (TLS) 1.2 is the default protocol for Platform Service Controller 6.7 by default, while TLS 1.2 is not supported by default on Windows Server 2008 R2
Resolution –
Enable TLS 1.2 on Windows Server 2008 R2.
Note: This procedure modifies the Windows registry. Before making any registry modifications, ensure that you have a current and valid backup of the registry and the virtual machine.
- Navigate to the registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols
- Create a new folder and label it TLS 1.2.
- Create two new keys with the TLS 1.2 folder, and name the keys Client and Server.
- Under the Client key, create two DWORD (32-bit) values, and name them DisabledByDefault and Enabled.
- Under the Server key, create two DWORD (32-bit) values, and name them DisabledByDefault and Enabled.
- Ensure that the Value field is set to 0 and that the Base is Hexadecimal for DisabledByDefault.
- Ensure that the Value field is set to 1 and that the Base is Hexadecimal for Enabled.
- Reboot the Windows Server 2008 R2 machine.
- Now re-initiate the migration assistance tool it worked perfectly.
Issue 10 – Error: Internal error occurs during vSphere ESX Agent Manager pre-upgrade checks during Stage 2 of upgrade.
I faced this issue while upgrading vCenter appliance from 6.0 to 6.5
the log shows below error —
Waiting for VMware ESX Agent Manager.
WARNING: VMware ESX Agent Manager may have failed to start.
Cause: This issue occurs when the /etc/vmware-eam/eam.properties file is empty on the source vCenter Server Appliance.
Resolution: To recreate the eam.properties file.
IMPORTANT: It is strongly recommended to backup the vCenter Server Appliance before following this procedure.
Hope you liked the common vCenter 6.5 upgrade issue and its troubleshooting steps. You can check vCenter pre-upgrade check to avoid such issues.
Thanks very much, this helped in a time of need!
Happy to help:)