LG Optimus L90

[AC Question]

Hi there. I recently put in a new Firmwire into my phone, after i wanted to unroot it.
Now my system apps text are all numbers instead of their proper name.
Launcher is M84525
Messaging is T25549
Dialer is T91116
ect ect

I don't know why this has happened?
Is this a virus or a bug or something?

Please Help Me.

T-Mobile
LG Optimus L90 D415