The 'Personal hotspot' option is gone from my iPhone 4. Why?

Solution 1:

Make sure you have an APN + Username & password set under Settings > General > Network > Cellular Data Network. The bottom option "Internet Tethering" has to be filled in to enable Personal Hotspot.

Apple KB article - iOS: About cellular data network settings (viewing or editing the APN)

Solution 2:

Today I get the option back. After 6 month I found Onavo app was the reason to disable "personal Hotspot". I just uninstalled it.

http://getsatisfaction.com/onavo/topics/my_personal_hotspot_configuration_has_gone

I wrote an email to Onavo support about it and got this reply

Dave NOV 09, 2011 | 06:44PM IST Hi Jitendra,

Thanks for replying.

We're sorry to hear that, still trying to find a solution for this. Our team is working on several solutions, will update soon. Regards,

Onavo Support http://onavo.com