Unfortunately, I am still seeing this with the snap in edge (version 21.04.2+git1.2719c57c, revision 2398).

Full crash report: https://paste.ubuntu.com/p/9yf3FY8kTx/

This is the backtrace:

Traceback:
 Traceback (most recent call last):
   File "/snap/subiquity/2398/lib/python3.6/site-packages/subiquity/client/client.py", line 364, in run
     super().run()
   File "/snap/subiquity/2398/lib/python3.6/site-packages/subiquitycore/tui.py", line 374, in run
     super().run()
   File "/snap/subiquity/2398/lib/python3.6/site-packages/subiquitycore/core.py", line 128, in run
     raise exc
   File "/snap/subiquity/2398/usr/lib/python3.6/asyncio/events.py", line 145, in _run
     self._callback(*self._args)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/raw_display.py", line 404, in <lambda>
     event_loop, callback, self.get_available_raw_input())
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/raw_display.py", line 502, in parse_input
     callback(processed, processed_codes)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/main_loop.py", line 411, in _update
     self.process_input(keys)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/main_loop.py", line 511, in process_input
     k = self._topmost_widget.keypress(self.screen_size, k)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/wimp.py", line 648, in keypress
     return self._current_widget.keypress(size, key)
   File "/snap/subiquity/2398/lib/python3.6/site-packages/subiquity/ui/frame.py", line 36, in keypress
     return super().keypress(size, key)
   File "/snap/subiquity/2398/lib/python3.6/site-packages/subiquitycore/ui/container.py", line 178, in keypress
     upkey = self.focus.keypress(tsize, downkey)
   File "/snap/subiquity/2398/lib/python3.6/site-packages/subiquitycore/view.py", line 107, in keypress
     key = super().keypress(size, key)
   File "/snap/subiquity/2398/lib/python3.6/site-packages/subiquitycore/ui/stretchy.py", line 159, in keypress
     return self.top_w.keypress(top_size, key)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/decoration.py", line 840, in keypress
     return self._original_widget.keypress((maxcol,maxrow-top-bottom), key)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/decoration.py", line 622, in keypress
     return self._original_widget.keypress(maxvals, key)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/container.py", line 1590, in keypress
     key = self.focus.keypress(tsize, key)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/container.py", line 2271, in keypress
     key = w.keypress((mc,) + size[1:], key)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/decoration.py", line 840, in keypress
     return self._original_widget.keypress((maxcol,maxrow-top-bottom), key)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/decoration.py", line 622, in keypress
     return self._original_widget.keypress(maxvals, key)
   File "/snap/subiquity/2398/lib/python3.6/site-packages/subiquitycore/ui/container.py", line 178, in keypress
     upkey = self.focus.keypress(tsize, downkey)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/decoration.py", line 622, in keypress
     return self._original_widget.keypress(maxvals, key)
   File "/snap/subiquity/2398/lib/python3.6/site-packages/subiquitycore/ui/container.py", line 178, in keypress
     upkey = self.focus.keypress(tsize, downkey)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/wimp.py", line 540, in keypress
     self._emit('click')
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/widget.py", line 460, in _emit
     signals.emit_signal(self, name, self, *args)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/signals.py", line 265, in emit
     result |= self._call_callback(callback, user_arg, user_args, args)
   File "/snap/subiquity/2398/usr/lib/python3/dist-packages/urwid/signals.py", line 295, in _call_callback
     return bool(callback(*args_to_pass))
   File "/snap/subiquity/2398/lib/python3.6/site-packages/subiquity/ui/views/installprogress.py", line 260, in ok
     self.app.remove_global_overlay(self)
   File "/snap/subiquity/2398/lib/python3.6/site-packages/subiquity/client/client.py", line 398, in remove_global_overlay
     self.global_overlays.remove(overlay)
 ValueError: list.remove(x): x not in list