In the past I've been using a script so people can see what music I'm listening to by inputting !np, however it no longer works.
The format I'm using is this:

on *:TEXT:!np:#:{ msg $chan MESSAGE }

But it simply doesn't return anything.
Have I missed a change in the script format?

The code is correct, check into your remote file if you have any other ON TEXT event into the file, if yes try to create a new file via Script Editor (File -> New) and paste there this code, also check if you have the remotes off first (/remote on).