[Bruce Milliken]

Ok, here's the deal. Ever since yesterday afternoon I've started to get random SIM card errors. I'll unlock the phone and the error will be on the screen. It takes me doing a soft reset to get the phone to work again. Any ideas on what could be causing this?

[MDK22]

probably a bad / dirty (something on the contacts) sim - replacing the sim would be my first attempt to remediate. Alternatively, POWER OFF the device, remove the sim, shoot some compressed air into the slot to blow it out, then re-insert the sim.

Phone = Lumia 1520 ??
Carrier = ??

[Bruce Milliken]

Phone = Lumia 1520 ??
Carrier = ??

Lol sorry, 1520 on at&t

[MDK22]

IF :
- you replace the sim & it still fails
- you didn't get any moisture in there

you probably need to return the device for service (either AT&T or MS / NOKIA). I'd check the warranty status here :

Nokia Lumia 1520 - Warranty and repair - Microsoft - USA

[cmsainz]

Hi, just in case, try to liberate memory space in your phone, I had the exact same problem and now is solved and working very well.

I've done a lot of things, like clean/replace the SIM card, rebooting several times (mine is Lumia 920) I was even looking for a new phone.

Everybody said that I was the screen, because everytime got locked, so, try liberate some memory. My phone was FULL.

Cheers.
Carlos