Plesk login page shows a blank screen.
links like https://plesk.example.com:8443/example.html are successfully loaded.
Websites are accessible.
sw-engine process is hung.
Connect to the server using SSH.
# pkill -f sw-engine-*
Run the the following command to show if there are any leftover process that were not killed in previous step, for example:
# ps auxww | grep sw-engine
psaadm 7478 0.1 0.6 322832 6576 ? S 05:41 0:00 sw-engine-kv
root 7479 0.0 0.9 482148 10192 ? Ss 05:41 0:00 sw-engine-fpm: master process (/etc/sw-engine/sw-engine-fpm.conf)
Kill the processes listed above:
# kill -9 7478 7479
# service sw-engine start
Start the "Web-Socket" service as well:
# service plesk-web-socket restart