defender keeps asking to update old security keys

Defender keeps asking to update old security keys
I have done it earlier last month and then just did it 4 times in a row as well as clearing my cache
and now I can't do any work as I receive 404 errors as I save a page

This page isn’t working
wildcatzindoorsports.com.au is currently unable to handle this request.
HTTP ERROR 500

Unable to edit pages.

PS: I have succuri on this site as well which has caused issues in the past