I'm using ArcGIS Pro version 2.4.0 and virtually every time I attempt to adda legend to my layout, it causes the program to crash. I draw a box with the tool but when I let go of the mouse, no legend appears, the drawing tool remains and I can't interact with ArcGIS Pro at all. I have to kill the program from Task Manager. At this point it's so frequent that I always save right before adding the legend so I can try adding the legend and then just open it up again once it has crashed. What I find especially strange is that it never crashes when I boot it back up again. Any thoughts on what might be causing it?
It it is happening all projects and you have cleared your caches you might want to try an upgrade of Pro or try a repair of the software (Add/remove programs, remove, repair)
One thing that I see in the internal reports is a GeoSoft Plug-in (ntdll.dll) will cause the issue. If you have this plug-in, uninstall it and try your workflow again. Another thing to try is perform a repair install. Open the Control Panel>Programs and Features, right-click on ArcGIS Pro and select "Uninstall/Change", and select Repair and run the installation. That might fix it too. Good luck!