The message seems to mention a plugin called “Conflict Finder,” which you have probably installed. That’s apparently where the message comes from. Check out this message with Conflict Finder. If you have any questions, you can find their support forum here: https://wordpress.org/support/plugin/conflict-finder-wp-fix-it/
Otherwise, you can also deactivate this plugin and see what happens. If it is a server-side error, it should be found in the error log in the hosting. You can find it in your hosting area. If necessary, the support of your hosting can help you.
Alternatively, you could also enable debugging in WordPress. How to do this is described here: https://wordpress.org/support/article/debugging-in-wordpress/ – also here the support of your hosting can help you if necessary to edit the file accordingly.
In both cases you should be able to see what the cause is in the logfile.
