I'm working with old Flash based Web Client on a vSphere5.5 system. I have used the Flash workaround found here: https://kb.vmware.com/s/article/78589 and modified the mms.cfg file on a Windows7 machine and successfully logged in with the Web client.
I think I first navigated to the VDP section to check on the backup appliance (which I think has an issue). I then went to one of the VMs in inventory, a Windows Server 2008R2 to try and see if I could use it to also connect to the Web Client. I took a snapshot of the VM and continued working until I realized this issue with logging into the web client.
This VM that I snapshot is was deployed from a template. I read that these VMs can cause issues with Web Client login: https://forums.whirlpool.net.au/go?https%3A%2F%2Fwww.techheights.com%2Fcall-propertycollector-retrie...
Unfortunately I had already deleted this VM and removed the template from inventory before reading this. I also read that plugins can cause this issue with the Web Client so I removed the VPD plugin using the vSphere MOB. I have also restarted the Windows vCenter. The thick client works fine but just no the Web Client.
I've enabled Debug logging on the Web Client and vCenter but I can't see anything in the logs related. Anywhere else I should be looking?
Edit:
I haven't had any success with this. One of the error messages I received from one of the browsers (different browser trying to login give different error definitions) was from this KB https://kb.vmware.com/s/article/2060114
I tried removing the cached directories for both the VDP and VSA plugins but I'm hesitant to remove the VSA manager plugin in the MOB as it may be difficult to reinstall (also uses Flash) and it's required for managing the storage.
I have a backup of the Windows vCenter server from which I can revert to a restore point that's about 12 months old. Since that backup there would have been a few VMs created and deleted and maybe some network modiffications.
What is likely to happen to vCenter if I revert to an earlier restore point that isn't aware of some of the changes in the environment?
It is hard to imagine how the VM/snapshot can cause problems to the vSphere Web Client - and your second link is pointing to a non-existent topic in the VMware community. I am not certain we can solve this in a single iteration so I'd suggest first having the problematic plugin isolated by disabling each plugin (not uninstalling the vCenter extension from the MOB of course).
You'd not get the desired result of disabling the plugins by deleting the cache folders. If a plugin cache folder is not found the vSphere Web Client would re-download the plugin zip from the VSA/VDP appliance. You can confirm this by checking the vsphere-client-serenity folder after restarting the vSphere Web Client and verifying that the plugin cache folders are back.
What you can do instead is copy over both plugin folders within vsphere-client-serenity folder as a backup then delete the contents of the original folders. You should have the following tree:
...
|
+-- vsphere-client-serenity/
|
+-- ...
|
+-- com.vmware.vdp2-x.y.z
| |
| +-- (EMPTY)
|
+-- com.vmware.vdp2-x.y.z-backup
| |
| +-- plugins/
| |
| +-- plugin-package.xml
| |
| +-- ...
|
+-- com.vmware.vsa-a.b.c
| |
| +-- (EMPTY)
|
+-- com.vmware.vsa-a.b.c-backup
|
+-- Whatever the content of the script plugin - my memory is failing me ... :P
Finally, restart vSphere Web Client once more.
Reverting any of the plugins is as easy as deleting it's empty folder, renaming the backup counterpart and restarting the vSphere Web Client.
Unfortunately your second link does not open - probably because of some proxy issue in your org.