New Error on layout not found

"Error on Layout Not Found".
For further information.
This problem is known and has already been encountered in 2020 by other users.
See the support response here: Error on layout not found.
It is 8/2/2021 and I have just had this anomaly with our CMS in V2.3.8.

The Layout cannot be edited, but the preview is correct and it is possible to create a copy of the layout in error.
The solution will be to replace the layout in error with its copy. When the copy is validated, the erroneous layout must be deleted.

Help the community.

A bug was already logged for this. You can track progress here: