I have the same problem on my Ipad after upgrading to iOS 6 (as does my partner)
I rang my carrier (Optus) and my sim card shows as not being activated.
I have to ring them to re-activate the sim card on Monday
I restored the ipad but has not fixed the problem all settings are correct
Hope this helps
Please help! I receive cannot activate cellular network and it started out of nowhere yesterday. I depend on the phone. I have used the same phone and provider without chagnes to my data plan which has data. I reset netowrk settings. When It first happened I restarted the phone and it fixed the problem for two hours, then bam its back again. Reboot doesn't work. Reset netowrk settings doesn't work, power off an don doesn't work, synching with itunes from the laptop doesn't work. I can't believe there isn't a clear answer to this here. What is causing this problem? You can see the spinnign whell for a few seconds then the error occurs. I have a netowrk signal. I use 3g usb modem from my laptop to post htis message so 3g is working. Please tell me how to fix this problem!
Interesting thread! I got here because I got the following messages after I turned off wi-fi and turned on cellular data and data roaming to see if I could send an email. I connected to Telus 3G with strength of 2 bars.
Could not activate cellular
PDP authorization failure
Cannot Send Mail
The connection to the outgoing server
Additional Outgoing Mail Servers
can be configured in Settings >
Mail, Contacts, Calendars
Can any level 9 or 10 member of this community tell us where to look to make sure all key settings are checked and set up properly for cellular and data roaming. Note that Apple Mail and Yahoo Mail work fine from the ipad when wi-fi is enabled. I also have a global sim card in the iPad that will (hopefully) connect to any carrier in the area. The sim card required an APN description.
After researching more threads, this one from AU and the UK, the solution seems to be:
>settings > cellular data
turn roaming off, turn cellular off,
>settings > safari
clear cookies and data
(one guy indicated to clear history, but I didn't do that and this solution seemed to work anyway)
power off your iPad and wait 5 minutes
(why 5 minutes, I don't know but it doesn't work if you turn on your iPad too soon.)
When you turn the iPad on again:
>settings > wi-fi
>settings > cellular data
cellular data on, roaming on
Go to mail and send your messages. You might have to try this a couple of times. I did.
I also got the same error message when I tried to send email a few days later.
I followed the same solution and the email was sent on the 3G network.
It is a pain, but it worked, so I am not complaining.
Hopefully someone can explain why you have to clear cookies and data to get your cell data connection to activate.