Hello,

I am using a hidden field to assign a usergroup.

It is a required field, this makes registration impossible without the correct url to populate the field with value. Great!

But when one tries to register from registration page, without this field populated, the error on top shows empty (see attached screenshot).
I want it to say something like: "Registration is only possible by invitation, please contact an administrator."

So my question:
How to add a language string for this?

Thank you