How to reslove "we apologize for any inconvenience, but we've made the site read only while we're making some improvements"?

Power Shell

• Powershell
• SQl

Add-Pssnapin Microsoft.SharePoint.PowerShell
$SiteAdminstration = new-object Microsoft.SharePoint.Administration.SPSiteAdministration('Your Site Collection URL’)
$SiteAdminstration.ClearMaintenanceMode()


How to unlock the site?

Add-Pssnapin Microsoft.SharePoint.PowerShell
Set-SPSiteAdministration -Identity "Your Site Collection URL" -LockState "Unlock"