AH, the KJV is DEFINITELY a protestant book. ‘Sorry for your ignorance. Catholics use it? For what? Not mass.
Yes JA, the KJV is an English version of the Bible based upon the Latin Vulgate. So yes, if you're using the Vulgate for Mass and I'm using the KJV, we're seeing the same text but in a different language.
If it makes you feel any better, how about I show you the same text from the Vulgate?
Mat 6:14-15 VUL - [14] si enim dimiseritis hominibus peccata eorum dimittet et vobis Pater vester caelestis delicta vestra [15] si autem non dimiseritis hominibus nec Pater vester dimittet peccata vestra
Happy now? The meaning of the verse is still the same.