Mainly caused when an update has been interrupted during process. WordPress automatically creates a “.maintenance” file which makes the website temporarily unavailable. During this maintenance visitors will see this message:
Briefly unavailable for scheduled maintenance. Check back in a minute.
In case you run into this, do not fret, the solution is pretty simple. Just follow this steps:
Step 1: Access your hosting Control Panel, in case you don’t have, you can get this from your webmaster or site administrator.
Step 2: Open up your File Manager
Step 3: Browse your public_html folder or the specific folder where your website is located.
Step 4: Look up for .maintenance file
Step 5: Delete the file and you’re done.