(Gramps 5.1.3-2 on Win10)
I accidentally close my Tree too often. I’m not even sure what keystroke is closing the Tree.
But usually when it happens, I’m drilled down in a huge stack of spawned windows and trying to quicly ‘ok’ them all (in the right sequence) to get back to the top. (i.e., adding an Event in a heretofore unknown nation to a new Mother in a new set of parents means the spawned window hierarchy = Family+Person+Event+Place+4 enclosing Place levels)
Somehow, I manage to close the Tree too. Suddenly, my Clipboard objects all show as broken, my Undo history is flushed and the Go menu does… unpredictable things. Reloading restores the clipboard broken links.
Unloading a Tree (without a confirm) can really interrupt my workflow.