Error Message please help?!?

[DarcKnight767]

Lately, I've been getting this error message on my LG Connect 4G, "Sorry! The process com.android.phone has stopped unexpectedly. Please try again. Force Close." And it happens randomly, or better yet, it happens when it tries to connect to 4G. At the top i see the 4G sign, but then it cancels out and then the message appears. I'll be typing a text message and boom it pops up. I'd be on the internet and boom. I'd just be on the homescreen and boom. And when it pops up, im forced to hit "Force Close" and when I do that, I lose my signal. And then on the unlock screen, it says "Emergency calls only" and then at the bottom I see "Invalid SIM". So would it be my SIM Card? Or something else? What can I do to return it to normal? I've done the factory reset twice but it didn't fix it. Could it be the battery? Ever since this started the back of the phone has been getting hot and the battery doesn't last as long as it used to. Please help me, please. Thank you

 

[friedtators]

What applications have you recently installed? Have you considered something you have done corrupted something?

 

[DarcKnight767]

No I didn't consider that.. What could've corrupted it?