As every site uses multiple plugins and themes, they might conflict. If your site crashes and/or shows an error message, most probably this happened with your site.
The first step to resolve this would be to update the plugins to the latest version. By plugins, we mean the plugins that are developed by us as well as others.
To do this, go to the Plugins menu and see if any of the plugins shows an update notice. Clicking on the Update Now will do the job.
If you still see the error, please reach out to us.
Related: My site doesn’t show the update notice, what to do?