Exclamation mark appeared on phone

[Oranges123]

What does this sign mean when it appears?

I was using the phone today and suddenly this big white exclamation mark appears similar to how you get the spinning cogs. Phone was stuck there for a few minutes unresponsive but then it just reset after a bit and came back on.

 

[Kavu2]

It likely means there was a problem of some sort. But your auto reset seems to have resolved the issue.

If the the exclamation mark returns and and phone is unresponsive, then a soft reset is necessary to return to normal as stated in this MS KB2749480 article
Your Windows Phone 8 doesn't work or respond as expected

If your phone is unresponsive, it might display a big exclamation mark, a combination of a gear and lightning bolt, your phone manufacturer's logo, or a pair of gears:

If your screen displays any of these images, try this: Press and hold both the volume down button and the power key for 10 seconds. This should get your phone to reboot and respond properly again.

 

[unstoppablekem]

It likely means there was a problem of some sort. But your auto reset seems to have resolved the issue.

If the the exclamation mark returns and and phone is unresponsive, then a soft reset is necessary to return to normal as stated in this MS KB2749480 article
Your Windows Phone 8 doesn't work or respond as expected

If your phone is unresponsive, it might display a big exclamation mark, a combination of a gear and lightning bolt, your phone manufacturer's logo, or a pair of gears:
http://support.microsoft.com/Library/Images/2899952.png
If your screen displays any of these images, try this: Press and hold both the volume down button and the power key for 10 seconds. This should get your phone to reboot and respond properly again.

I never heard of this exclamation mark! Thanks for helping him!

 

[Oranges123]

Interesting thanks. Wonder what caused it, first time it appeared and didn't know what had happened. Hope it doesn't happen again as an exclamation makes it feel like it was a serious issue.

 

[Troy Osborn]

Thanks so much my phone got a little "damp" today at work and was working fine till the volume down button stuck so i turned it off hoping to reset turned it back on to exclamation mark and no matter what i did it wouldnt go away but you guys are my saviors today and it works like a champ again just like a Windows Phone should (Lumia 822)

 

[CostanzaC]

mine is doing the asme exact thing now...kept going onto vibracall and I shut it off hoping it would reset...the exclamation mark has been alternating to the nokia logo for the past 20 min but nothing is happening. can I try anything else?

 

[Devirupam]

my phone's screen showing (!) sign. I have done what is said. it worked. phone is on now. but power button & volume key is not working. clicking on power button showing Windows Feedback app. volume key stuck on 0. any solution?? (lumia 650)