My iPhone 5 suddenly ceased using iMessages. The phone is unlocked, has ios 9.3.2 installed, I have very few apps installed, and no new apps installed recently.
When I go to Settings > Messages > iMessage and try to toggle, I get the following:
Turn on cellular data or use Wi-Fi to set up iMessage.
However, cellular data is enabled in Settings > Cellular > Cellular Data. Cellular data seems to be working fine in Safari, apps, etc. I get the same behavior with LTE or 4G cellular.
I have tried all of the following based on hunches and information gleaned from non-stackexchange sites:
- Restarting Messages
- Restarting the phone
- Resetting network settings
- Resetting the phone's passcode
- Resetting the AppleID account password associated with this phone
- Erasing all content and settings from the phone, and then restoring from backup
- Ejecting the SIM card, and replacing it.
How to get this basic functionality to work again?