Help SIM card is invalid

[AndriodUser7483527]

So I have an LG LS720, and last summer I believe I burned the battery out because I left it charging too long. So anyways, I got a replacement off the warranty, (same model) however I did not receive a new SIM card as I had not turned it in with the rest of the phone. So I put the old SIM card in, and ever since then my phone has said, "SIM card is invalid." This may be unrelated but I also noticed that ever since then, my mobile network doesn't work properly. So any advice on how to fix this?

 

[Hadron]

Get a replacement SIM.

 

[AndriodUser7483527]

go to settings > about and check if you have a baseband. also check if your IMEI is intact

They both have values. Is that what i was looking for?

 

[jmacguire]

The only time I got that is before my phone was unlocked. I ran the s4 unlock tool for international use/unlocking and the message was gone after reboot.