A message explaining why I cannot create this folder could be really helpful (e.g. something like your comment above).
My scenario was that I created a vault, and then tried to create it again using a new password.
I could not understand why button "Create" would not do anything (was it a GUI issue? Cryptomator? Cyberduck? Google Drive?), and nothing would be shown in the log. Maybe at least show a message in the log?