Detail pages disappearing - I didn't delete them

I have column that is a link to a detail screen. When looking at the column properites, I see this message in yellow:

This action link uses legacy styling. Apply a Theme action style to match your current theme.

The detail page no longer exists. It has been deleted. I did not delete it.

What happened? Anyone else see this?

Hi @GregJohll83463, I suggest reaching out to support@knack.com to assist with this one, and provide as much detail as possible, as this may be hard to diagnose/reproduce.