Hi @Mario Nunes
see, if you have deleted the project that time related project key also deleted.
If you want to edit the already exist project then you should be choose Edit project not delete the project.
as @Ligia Cindea mentioned above comment might be it works once you have performed Re-indexing.
You need to clear the old key out of the database. But, it's being retained to prevent you damaging your historical data - it's only safe to clear the old key out if you have never moved issues from the deleted project out to anywhere else (or, if you have, you delete them as well)
For JSM June Challenge #2, share how your non-technical teams like HR, legal, marketing, finance, and beyond started using Jira Service Management! Tell us: Did they ask to start using it or...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events