I have a galaxy grand prime and it keeps saying invalid sim

[AC Question]

I've tryed wiping the sim off, blowing on it. I've powered ir down and restarted it but nothing is working

 

[Rukbat]

Either the SIM is defective, the SIM port in the phone is defective or you're using another carrier's SIM and the phone is still SIM-locked. See your carrier - they can usually help with SIM problems.