That's the 4th preset from Rename Toolbar v3 (english and french) without any real changes to the code.
Trying the original, it seems to work fine as-is. It only prompts for the first file and then applies the same things to all the others. (It asks for the search string, then the replacement string, but only once for each.)
If you don't want it to prompt for the replacement string, it's a fairly simple change.
Although I would do things differently, without using a script for any of this, since you can do it in a simple, single-line button or hotkey:
Rename FINDREP PATTERN="{dlgstring|Enter text to remove:}" TO
Everything in that line is explained under: