cannot verify server indentity

What are you trying to do? Are you trying to set up your mail account information?

I have the same problem. I was on the internet and checking my mail when the message appeared. Now, I am not able to use the Ipad at all.

Try this, hold the power and home buttons at the same time (keep holding past the swipe to shut down bar if/when it appears) until the Apple Logo appears, THEN let go of both buttons. This worked for me.

I'm having this same SSL certificate problem today on my iPod Touch G4. Dave's solution did NOT work for me. Instead the procedure messed up my iPod Touch such that it was impossible to get past the lock screen after the reboot. I had to then reboot the iPod Touch 4 a second time. The same SSL certificate verification warning immediately greeted me. Knowing the potentially critical nature of a fraudulent SSL certificate I will not be hitting 'continue'. I'd rather call Apple as it is their certificate causing this warning:

In my case, this problem is specific to the SSL certificate for MobileMail, the mail server for MobileMe. I've reviewed the certificate details myself and found nothing at all wrong with what is listed. The listed certificate authority is VeriSign, IOW Symantec. I have zero respect for anything Symantec, but I cannot imagine the company has managed to yet ruin VeriSign certificates. However, Symantec is currently the victim of a vast hacking attack which may well have resulting in fake certificate creation similar to the problems this past year at Comodo et al. As a Mac security specialist, I want to know exactly what is going wrong here.

I solved the problem by deleting my MobileMe account on my iPod Touch and setting it up again from scratch. I made sure to keep all my data at the time of deletion, then merged it into the newly setup account. FINALLY everything is working again. Apparently something regarding the mail.mac.com IMAP server settings became corrupted such that it could not identify what was actually a valid SSL certificate. (o_0)

Started having this problem today (09/21/2012) with the iOs 6 update.

But I am not sure what caused this issue - since Facebook had an update at the same time of an operating system update.

Got a Cannot Verify Server identity error. Facebook cannot verify the identity of "webdav.facebook.com" Would you like to continue anyway. tried to use the [Continue] button - but it didn't work, kept getting the Networ Error.

Did a hard reboot, closed the app etc. cant get rid of the error.

Removed Facebook link from iphone - gonna look for ios6 threads now

Found the problem - apparently while trying to do the fix for the Passbook (change date on phone for a year in the future in order to launch apps) I forgot to change my date back to today - it caused the network error.

Once I changed the phone date back to today - the Facebook and Safari Server errors went away.

oh my god i literally did the EXACT same thing and have been stuck trying to figure it out for the past hour! Thank you thank you thank you!

TThank you