can't sign into a specific apple id for imessage

i have an ipod touch 6th generation and i can't sign into my apple id, i have another one that signs in perfectly fine. i've changed the password on the main id and i've tried signing in on multiple devices. also, when i go into the imessage app and try to sign in, it shows up that i am signing in, then pops up

"FaceTime Activation"

"An error occoured during activation."

"Try again."

even though i'm signing into imessage.

help please.