This is not the normal behavior after a license expiration and restart of a Check Point system.
Once you got the new license you should always be able to open SmartUpdate in order to attach the license to your Check Point systems.
R77 Management licenses typically don't 'expire', they just run out of support and you need to renew them (see Contract tab within SmartUpdate -> should always be 'Yes'). Your system doesn't just stop after the support contract expired.
However, do you have a cplic print or screenshot of your license within your UserCenter account available?
Your management server issue most likely results from the power outage. As you are also unable to login via SSH, you'll need to start troubleshooting the system in order to get it up an running again. Are there any error messages shown during start startup of the management server?