It sounds like one of your administrators either removed it, flipped the project over to a non-Service-Desk type, or Service Desk has expired/been-removed.
If it's the second, then you should be able to recover it by getting them to change the project back to the right type.
For the third, re-enable or re-licence it.
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
We're bringing product updates and pro tips on teamwork to ten cities around the world.Save your spot