This is an article where the main focus is to solve the error message as in the title of this article. It happened in the middle of the update process of the wordpress core. There is a message informing that a new version of the wordpress is available. It suggests to update the wordpress version. While in the middle of the update process, accidentally by mistake refreshing the page. Since the update process stop, try to redirect the page back to try to redo the update process. In the end, the web and also the wordpress admin page is not accessible.
The following image is what the page looks like :
In this section, the focus of the writing is on the solution of the problem above. At least, there are two solutions in order to solve it. The first one is to remove a certain file in the wordpress site installation. The second one is to update the wordpress manually. This article will explain on how to perform the first solution. The ose solutions are in the following list in order :
1. Remove the file with the name of .maintenance. Every update process of a website using wordpress as its main framework will generate file .maintenance. The file exists in the root folder of the website. Just in case, move it to another location to prevent more serious damage. So, the file is still exist if there is a need to restore it back. Create a new folder to contain the file. For an example :
root@hostname:/var/www/html/my-web$ mkdir temp root@hostname:/var/www/html/my-web$ mv .maintenance temp
2. After removing the file, the website will return back to its normal condition.
3. Just refresh the page and then try to update again.
4. If the process fail, just do the second solution. It is a process to update manually. Read the following article to update the process manually in this link.