How the heck am I supposed to be able to read this?
I can make the editor window as wide as my screen, I don’t see more of the message. Doesn’t show up in “Problems” either…
Does it not show up in the Terminal window either? Either way, I hear you. And not to be all old-man-yells-at-cloud again, the way GhPython handles error messaging is just much simpler and user friendly, especially compared to the new IronPython component 
250219_ErrorMessages_00.gh (5.1 KB)
Are you able to post a code fragment that reproduces that error message? Other errors here display in the Terminal window and full text displays if you hover the cursor over the red area, so it looks like this might be error specific (or error category specific).
You could rename your variables shorter to see more of the message if that would help diagnose.
f = Rhino.Geometry.Brep.CreatePlanarBreps
x = loop_crvs
f(x)
OK, I just restarted Rhino and now I have the error message in Terminal as well as in the hover tooltip. Didn’t before.
I had already noticed that something was wrong earlier, because a double click on the component would no longer open the editor, it always brought up the canvas search. I had to right-click and choose “Open Script Editor”. After the restart double-clicking to open the editor works again.
No idea what went wrong.
BTW the error was
System.InvalidCastException: Unable to cast object of type 'Rhino.Geometry.Polyline' to type 'Rhino.Geometry.Curve'. So I was trying to pass a list of polyline objects - which I thought were already curve objects - to Brep.MakePlanarBreps().