Comment # 3 on bug 1118870 from Wolfgang Bauer

(In reply to Stephan van den Akker from comment #2)
> The Dutch language error message on the first line of output of locale
> translates to:
> "Cannot set LC_ALL to default locale: File or directory does not exist"

And that's likely the reason for your problem, I think.

I can reproduce that error message (and k3b's warning) with your
plasma-locale-settings.sh.
The offending line is this:
export LC_MONETARY=en_NL.UTF-8

Is your filename problem fixed if you remove or comment out (i.e. put a '#' in
front of it) that line with a text editor?
You need to logout/login or reboot to "apply" the change.