'Fields Required' error message translation

[Māris Leimanis]

Hello

I have problem with translation for Field Required error message.

I set that Fix Version is required on transition with Validator - Update parameters of the 'Fields Required' Validator for this transition.

Then using translation I wanted to find this Fix version is required. Fix version change translation when I change language, but is required that I need can't be find in https://translations.atlassian.com

Found these keys, but translations not working on current error message, so they are not what I need.

admin.common.words.is.required

issue.field.required 

Is there any way, that this text comes without key or can't be translated or is somewhere inside code files?

P.S. If any admin can move this to question section. Made mistake and pressed on Discussion