A short background: had to duplicate a site and then delete everything (~60 pages neatly in folders & subfolders) except that one page I needed (really would appreciate cross-project components, hint hint). When weeding out the unnecessary pages and folders, webflow crashed several times. And when I say crashed, I really mean that - no amount of soft or hard refreshing would bring it back.
Another curious thing that occurred two times was that when I reopened webflow (after brower restart or in a new tab), it annouced during loading something in the essence of "the folder X cannot be found, the page Y inside it has been moved to the root folder". Note that said X was not what I was attempting to delete; it was always the last folder in the líst. And it truly did not exist in the list anymore. At least once, however, the mentioned X was resurrected after a browser reboot.
I could not reproduce what kind of deletion causes the crash but it is still happening. I suspect (without good reasons, though) that it has something to do with the order / position of folders to be deleted but can't say specifics.
Won't be posting site here but will send it to support via email.