With a Text List set up with a header, I can’t get a response using info(“matrixclickedframe”) for clicks on the Header.

Setting a procedure of simply Message info(“matrixclickedframe”) results in “BODY” if I click on any of the displayed records, but nothing if I click on the Header.

I thought I could work around it with: If info(“matrixclickedframe”) ≠ “BODY” but got no results that way either.

Double-clicks on the header trigger a procedure that runs on the currently highlighted matrix row.

It appears that single clicks on the header are simply not registering in any way.

I can’t duplicate this, it works fine for me. However, I am guessing that the problem is that you didn’t enable the Allow Header Clicks option, that would result in the symptoms you describe, except for the double click part. For me, if the Allow Header Clicks option is turned off I get nothing, for both single and double clicks.

See Clicks in the List Header on this page:

I do have Allow Header Clicks checked and have reviewed the documentation several times to see if I’ve missed anything.

Moving the file from Mojave to another computer with El Capitan nets the same results.

Solved - The Resizable Columns option disables it

Yes, because then the Text List itself interprets the clicks for resizing the column.

That makes sense - and would be worth noting in the documentation.