Do you know why I would I keep getting an Invalid SIMS card message on my Galaxy Grand Prime?

[AC Question]

I had my first Galaxy Grand Prime for 8 weeks and the Invalid SIMS card thing happened 6 times in that 8 weeks. Straightalk eventually replaced my phone. I just got my replacement last Thursday evening, set it up Friday and Saturday evening it happened again.

 

[B. Diddy]

Welcome to Android Central! They replaced the phone, but are you using the same SIM card as before? If so, the card itself might be the problem--ask Straight Talk for a replacement SIM.