Q: iOS 7.0.3 update install caused an invalid SIM  message. Help !

This is really bad.  I expect much better from Apple.  There are enough people here having this terrible experience with 7.0.3 and Sprint INCOMPATIBILITY that Apple should be more proactive to fix the problem.  They should at least ADMIT there is a problem with the 7.0.3, instead of making us jump through so many hoops with try this an try that.  My bet is that Apple neglected to even test 7.0.3 with Sprint based iPhone5.  This reminds me of the ObamaCare website.  No testing, just release it and see what happens.

Till 7.0 quality was perfect (even Betas!).

But since the dot releases Apple has made some mistakes (iMessage, Battery drain, etc..)

And no possibility to downgrade to 7.0!!!

(I understand that downgrade to 6 is not possible but within the same release?!?!)

I resetted Network Settings in iPhone.

Now since 1 week no problem.

Keep you updated. (i also ordered a new nano-Sim from my provider).

Yesterday after iOS 7.0.4 upgrade 2 times invalid/no SIM.

Now changed to new nano sim from the provider.

Let's wait...

After more than 1 week with new sim it seems to work.

Very strange as "old" sim was about one year old and never ejected and was clean!

I just got off the phone w Apple Care. I too upgraded my ipad mini w 3G  to iOS7 and suddenly couldn't get Verizon signal, but got a "No SIM card installed" message instead. All was fine until my upgrade to OS7. But all Applecare and I did was perform a "Reset all settings". After reset, I entered my wifi password back in then I turned OFF wifi and tried to get Verizon signal, WHICH TO  UTTER AMAZEMENT ACTUALLY WORKED! I did not have to pop out my SIM card so you all might try the all settings reset maneuver.

This is actually simply solved.....power off your ipad...not just switch off but hold down power button until you are asked to power off...now leave off for at least 20 seconds...this will allow the ipad to reset, so that when you turn it back on ( hold down power button again until apple logo is on the screen) The first thing you get should be a sim lock/ password...enter your code and you're on your way......you will have to do this every time you switch off/ switch on your cellular roaming...... unfortunately.

Same problem on my iPad. Tried restarting, resetting Network Settings and all of the rest of the suggestions in the Apple knowledge base. No luck with any of them.