As the error seems to be related to workflows and the ability to clone, I can think of the following possible causes, depending on the action which triggered the error:
Reviewing the underlying workflow in edit mode may provide a clue.
If you do not find anything else, I'd suggest you to create a ticket with Atlassian Support:
Badges are a great way to show off community activity, whether you’re a newbie or a Champion.Learn more
Hi Atlassian Community! My name is Shana, and I’m on the Jira Software team. One of the many reasons this Community exists is to connect you to others on similar product journeys or with comparabl...
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
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs