This happens to me fairly often now, but it was rare before I was on versions of SolidWorks 2024 or later (roughly).

The specific error text is as follows

The only problem is that when I edit the sketch, nothing is dangling. There are no hidden dimensions, and all of the sketch relations are defined and attached. I've even gone into the sketch and deleted every entity, drawn a new line with no relations or dimensions, and it still retains the error.