[[Module:headword]]

If you're not sure whether something will cause pretty much every headword to break, you should post your proposed changes in the GP first so another pair of eyes can go over it first. It's slower, but it's far better for the dictionary (and, by the way, for everyone's trust in you).

I was sure. It broke anyway.

So let me be clearer: if you can't trust your sureness about whether things will break, as appears to be the case, you need to ask someone else to take a look.

Also, why is there still a module error on pages like dodekafonia?

I don't see an error.