Can not login to VCENTER with either client or web client

[IHGVL]

We have ESXi 5.5 hosts with Windows VCENTER 5.5.  Recently we are now unable to login to the client and also can not login via web client due to Adobe Flash retirement.  

Logging into client produces this exact scenario is KB 2035510.

I have tried to reset certificates per another article, unchecked the “use Windows session” credentials, tried the original local admin account.  We currently are unable to login via client or web client to VCENTER, but we are able to login to all ESXi hosts.

I also tried the reset of administrator@vsphere.local through tools and .exe tool but it would not take that in the client either.  We are unable to use or try web client due to Adobe Flash End of Life.

Is there any suggestions to recover current VCENTER/vsphere OR download VCSA for another version and how to migrate from one failed vcenter to a new instance?

[e_espinel]

Hello.
If your infrastructure is small (say one vcenter server and 2 esxi hosts) and your configuration is basic (no HA) and does not require the statistics of the old vcenter server. The fastest way would be to discard the old vcenter server, install a new vcenter server and enter the esxi hosts in the new vcenter server, it requires the root user and password of each ESXi hosts.

You must have at hand the vcenter server configuration such as IP, name, domain ... etc.

You must also enter the old license in the new vcenter server.

In environments with old versions of VMware vSphere there is no other option than to use a old browser that supports Adobe Flash Player.

Personally I use the following combination, but only to manage VMware vSphere, to surf the internet I use a more current browser.

Firefox ESR 38.8 (32bits)

Adobe Flash player 29.0.0.113

Both the browser and the flash player must be configured so that they are never updated.

To login using the vSphere Web Client (Flash). You can instead open a Web browser and enter the URL for the vSphere Client: https:// ip_address/ui