I am guessing you already have a backup of your site when you downloaded from FTP.
So, I would suggest uploading/overwriting WordPress with a fresh copy. Simply go to http://www.wordpress.org, download WordPress latest version, and FTP the files straight into your domain folder and when prompt if you want to overwrite hit the yes button.
If I remember correctly, on most FTP clients this does not overwrite your existing plugins, themes, child-themes etc that are actually located within the folders you are overwriting.
For example, your current WordPress has a folder named wp-content (which contains your themes, child themes etc) and you will ovewrite this folder with the new WordPress wp-content folder. But this should not effect the theme and child-theme within.
Let me know how it goes after a clean WordPress 🙂
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This reply was modified 8 years ago by
dayley.
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This reply was modified 8 years ago by
dayley.