When you are updating wordpress automatically on the dashboard. Suddenly, you can not view your blog anymore. You will get the message ” Briefly unavailable for scheduled maintenance. Check back in a minute.” Now your blog got stuck!
In order to fix this you will have to access your server and remove a small file called .maintenance that has freeze you out from your blog.
You may or not be able to see the dot files with your ftp depending on whether you use secure access or not so for most it is best to go into your control panel. But using gftp the file .maintenance is visible. Go to file manager and locate the .maintenance file in the folder your blog resides in.
Delete that file and your blog will be up and running.
You will only get this problem when an update is not successful or your internet hang or disconnect half way. Hopefully this will save you.
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Thanks for the post it helps me.