i updated with latest update today and since then i can not assess through web portal. After little while a message of unable to reach server comes.
I have restarted hub 2-3 times with no change
Welcome to Hubitat. I would reach out to support directly.
Once you have registered your hub, it is no longer necessary to access your hub through portal.hubitat.com. You should be able to reach it via the local ip address on your network.
Does your hub have a DCHP reservation setup in your router?
If you've rebooted the hub (which, assuming you can't reach it via the web UI, means that you unplugged to trigger the reboot), your database may be corrupted.
i restarted few times and its working now