Trouble with iPhone 4 upgrade?

I have just performed a firmware upgrade to my iPhone 4. The upgrade was successful, but when I tried to start the phone I got this message: "Only compatible SIM cards from a supported carrier may be used to activate iPhone" It doesn't wanna go further, I have my SIM card from a Moroccan carrier, but it doesn't work now. It worked before properly. Does this mean that I have to buy a new phone? Any suggestions please?

You got 3 options, turn turn off the phone and turn it back on or take out the sim and put it back in or factory reset the phone.

Means the iphone 4 was unlocked, and by updating it you locked it to the original carrier.
you need the original sim that came with the iphone in order to use it.
or trade someone for a unlocked one.