I created a new issue type, and attempted to link it with a pre-existing workflow within a specific project.
This is the exact same process as carried out yesterday for a different issue type.
However, this time, I get the message "A issue type with ID '11509' does not exist.".
I deleted the issue type entirely, and created a new one (with a different name), and attempted to do the same thing again, but the error message came back again, with a different ID# value.
I looked through info available, but the best I could find was a suggestion to remove something from a database, which I am unable to access. If I go to the workflow, I can amend it with no issues, but the issue type created is impossible to link with *any* workflow.