SMF not working after upgrading

[peterish]

Dear Friends, My SMF is not working any more after upgrading. It just shows below message. I appreciate your help, and thanks in advance.

Upgrading the forum...
Don't worry, we will be back shortly with an updated forum. It will only be a minute .

[Powerbob]

You need to give us more details here! We are not not mind readers!

[Kays]

Have you tried logging in?

If you can't, open Settings.php at the root of your forums and change $maintenance = '2'; to $maintenance = '0';