Unable to access into Plesk or websites: Apache service not starting with: litespeed is not running

Symptoms

• Apache service fails to run on the server:

  # service httpd status
  [ERROR] litespeed is not running.

• An error is shown in Extensions > My Extensions > Litespeed:

  PLESK_ERROR: [LICENSE] License key operation failure: ERR LC.VT: Your trial license has expired -1 days. (If you have recently made a change to or a payment for this license and believe this message to be in error, please visit the License Status page to refresh your license status)

• Plesk panel and websites are not accessible on a first load and a refresh attempt fails with Connection refused.

Cause

Litespeed extension is enabled but does not have a valid license key installed.

Resolution

• Contact LiteSpeed support regarding the license installation.