Help SIM Card Removed: Please Restart

[nickdalzell]

My Boss has started getting this error at random, sometimes once a day, sometimes once a week. every time he hits 'restart' it starts working fine for awhile so i don't believe it's a bad SIM card. the S4 is a year old. The error is screencapped:

I am asking this to help him out. Personally i've owned S4s, Notes and the like and am quite familiar with Samsung and TouchWiz and i've never seen this error before in my life. His carrier is AT&T if it helps.

 

[jhawkkw]

If the sim card isn't bad or somehow worn, perhaps the part of the phone that reads it has some were or dust on it?

 

[nickdalzell]

i mentioned dirt getting under the battery cover, and it is at a very gritty job. his wife's phone (same thing, a Galaxy S4 on AT&T) is not experiencing any issues. he has his in an otter box. it's just random. once it reboots it works fine. i doubt the SIM is bad. were a certain crop of S4s having motherboard problems? I've never seen this error and i'm a Samsung fan.