Issue when Upgrading xibo docker 4.0.12 to 4.1.2

I want to upgrade my xibo docker to the latest version, I have followed the steps in the following link Upgrade and Switch to Docker Install | Xibo Digital Signage.
but it still shows “The CMS is temporarily off-line as an upgrade is in progress. Please check with your system administrator for updates or refresh your page in a few minutes.” on the login page