Repro :

Copy a board backed by a filter say named "Klingon"

You geta copied filter called "Copy of Klingon"

Copy the same base board again and it fails with :

Error message : Filter with same name already exists.

Its not handling the name clash properly.

Suggestion : start adding number suffixes until it succeeds or you get to 100 say.

eg

"Copy of Klingon 1"

"Copy of Klingon 2"