X, Y, Z has gone wrong on my site - diagnostic - safe mode

Try safe mode to see if that helps. In this guide click Disable scripts in preview.

Be sure to disable safe mode after you've taken care of the issue.

If your issue goes away then it is most likely an issue with your custom code.

At this point you will need to find out where your custom code has gone wrong.

You should follow up in a thread other than this one. This thread is a diagnostic tip, not an offer to solve specific issues.

If the issue does not go away then you need to dig further into your issue.

I have found that if I point to a thread with the safe mode diagnostic method that I've suggested to a poster, folks get confused by the original poster's issue and think it doesn't apply to their issue, hence the stand alone post.

Thank you for the info, unfortunately, I'm not getting anywhere just yet. I'll post elsewhere as well.