Here are the instructions of this article in the shortest way I could write them to restore WordPress to a fully-working copy:
- Download the latest fresh WordPress copy from here.
- Extract the copy on your computer.
- Open the
wordpress
folder on your computer and select all the files. - Open FileZilla, configure the connection to the FTP server and go to your domain’s
htdocs
folder. - Drag all the files from the
wordpress
folder to the right panel of FileZilla, check the box to overwrite the files on every upload and only on the active queue, select “Overwrite” and click on OK. This should upload each and every WordPress file from yourwordpress
folder to your domain’shtdocs
folder, and should take a while to complete. - Remove the
.maintenance
file on your htdocs folder if it exists. - Go again to your domain’s
wp-admin
page. If it asks you to do a database update, do it at this point. After that, you should have a fully working and fully upgraded WordPress website.