How to remove a screen which is no more listed as part of any Screen Schemes nor Workflows

[CDC]

I struggled to remove a unused screen.

While trying to delete one, I always got the following error message
Cannot delete screen as it is used in Screen Scheme

I removed it from Issue Type Screen Scheme -> removed from Screen Scheme.

It did not fix the issue, I could not delete the said screen.

It appeared to not be used anywhere

What should I do to be able to delete once for all?
Spoiler answer : Check workflow where you might have used it, it might not been displayed but still in use in one of them as a transition screen.

[CDC]

Solution to the issue reported above which I found and might help the someone from the community one day : The Devil's in the Details (of a or many workflows) in Screens page. Indeed it seems that Workflows info cannot be trusted as this field might not report a transition in use which uses the screen you want to delete without success

In my particular case as shown, it was used as a transition screen for the creation of an Epic in my project SOP

I edited this transition by specifying an alternative Screen which was ok for this workflow
I published the new workflow with this fix, 
Then, I went back to the "Screens" page and I could delete the screen I wanted to without any issue.
My problem was solved

[Kishan Sharma]

Good catch @CDC thank you for sharing