Remove Parenthesis at very end..

The only problem with replace is that it removes all ")" characters.

So if you have for example

ARTIST - TITLE (Remix) ft. ARTIST & ARTIST2)

You get as result: ARTIST - TITLE (Remix ft. ARTIST & ARTIST2 (So missing both end ")" characters.

I think better is to use:
The replace with Regular Expression Action and then as Regluar Expression enter
.{1}$.
As field enter TITLE (Not to use on _FILENAME)

As listed in Actions