Sometimes models are duplicated / deleted #19
Description
I have several models in a single (MPD) .ldr file. Sometimes I end up with duplicate models and missing models. I have not fully characterized the issue but I believe it (occasionally) occurs when I drag one in the list on the left to reorder them. It is a long list so it often has to scroll while dragging the item. I don't remember if this occurred on OS X Mavericks but it is occurring on Catalina.