About a week and a half ago, my Motorola e4 had a system update. After the update, my SIM Card no longer worked. I went back and forth between my old carrier (Virgin Mobile), Motorola and Cricket Support. I ended up buying a new SIM Card. Saturday I was able to replace my SIM but I'm still getting the "invalid sim card error." I've been going back and forth between Virgin Mobile and Cricket trying to figure out why my SIM isn't working. It works in another cricket phone but won't work on my phone. Saturday, I had contacted Virgin Mobile to put in a phone unlock request. After 48 hours, I was still getting the invalid sim card message. I was told to contact Cricket to reprogram my device after it was confirmed my device was unlocked from their network. I contacted Cricket today and they reprogramed my SIM card. I am still getting the invalid sim card error. I was told once again to contact my old carrier to get my phone unlocked. It is unlocked. I don't know what else I can do to see to remedy the problem. If anyone has any advice please let me know.