why there is exclamation mark on wi fi. I am facing problem after upgrading to lollipop 5.0 I have a Micromax AQ4501 mobile phone. I am getting an exclamation mark over the Wi-Fi icon. And I am unable to connect to Wi-Fi thereafter.

I have been facing this problem since a few days after I upgraded my phone to Lollipop 5.0. I tried many things like:


switching off and then on, 
replacing SIM from slot 1 to slot 2, 
switching mobile data and Wi-Fi connection on and then off


but all in vain. 

I called the Google call center but they were also unable to help me. 

I am able to use internet through mobile internet, but unable to use Wi-Fi with this phone. My Wi-Fi is working fine on other gadgets like my laptop. 

How can I resolve this problem?
in lollipop , '!' is shown usually when wifi is connected but unable to access internet for reasons like Sign-in into ISP webpage,etc .

i suggest u to turn off wifi router power supply and turn it on after 10 seconds,
this solved same problem for me