You try to test an Integration, specifically a Webhook, in GitLab. The URL is for Jenkins. You get "Execution expired." What could be wrong?
Possible solution #1
See if the GitLab's IP address or hostname changed. If the external_url stanza in /etc/gitlab/gitlab.rb uses an old IP address or FQDN, then that may need to be updated. You may need to run "sudo gitlab-ctl reconfigure" again. Then you may want to reboot your server.
Possible solution #2
Is there a firewall blocking connectivity over port 8080 (or whichever port your Jenkins server listens on)?
Possible solution #3
To find out more, go to the webhook job, click on "Edit." At the lower portion of the screen you may find more about the job.