I was trying to update the theme on one of my Wordpress websites and suddenly I got this error on both my Wordpress website on the same web hosting (even the one I was not working with !!) At first, I got this error: The site is experiencing technical difficulties. After disabling all plugins and switching to the 2019 theme, this error showed up. I have no idea how to solve this issue. I contacted to host admin and they-they said this is a Wordpress issue and not related to the host!
I look forward to hearing from someone to help. Thanks