No idea, Don. But, I had this error cropping up all over the place today in a couple of sections after I copied in some elements from another file.
Closing ArchiCAD, and re-opening the file cleared up the problem for me (whew!). Apparently some kind of integrity check is performed when a file is opened and that cleared things up for me. I tried a variety of things before I figured this out and could not trace the error down to any one particular element.
Weird.
Karl
One of the forum moderators
AC 26 USA and earlier • macOS Ventura 13.6, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB