Updated Debian and now getting 503 error

I used “sudo apt-get update && apt-get dist-upgrade” and now I am getting

Service Unavailable

The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

Apache/2.4.25 (Debian) Server at Port 4443

How do I either restore to prior version or fix this?

After several reboots it seems to be back on line

most likely a hardware issue. Check your power supply