Description of problem:
Just tried to open a revelation file.

Version-Release number of selected component:
gnome-passwordsafe-3.32.0-3.fc31

Additional info:
reporter:       libreport-2.10.1
cgroup:         0::/user.slice/user-1000.slice/user/gnome-shell-x11.service
cmdline:        /usr/bin/python3 /usr/bin/gnome-passwordsafe
crash_function: tree
exception_type: AttributeError
executable:     /usr/bin/gnome-passwordsafe
interpreter:    python3-3.7.5-1.fc31.x86_64
kernel:         5.3.8-300.fc31.x86_64
runlevel:       N 5
type:           Python3
uid:            1000

Truncated backtrace:
pykeepass.py:108:tree:AttributeError: 'NoneType' object has no attribute 'payload'

Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/passwordsafe/unlock_database.py", line 277, in password_unlock_success
    self.open_database_page()
  File "/usr/lib/python3.7/site-packages/passwordsafe/unlock_database.py", line 603, in open_database_page
    UnlockedDatabase(self.window, self.parent_widget, self.database_manager, self)
  File "/usr/lib/python3.7/site-packages/passwordsafe/unlocked_database.py", line 86, in __init__
    self.assemble_listbox()
  File "/usr/lib/python3.7/site-packages/passwordsafe/unlocked_database.py", line 116, in assemble_listbox
    self.current_group = self.database_manager.get_root_group()
  File "/usr/lib/python3.7/site-packages/passwordsafe/database_manager.py", line 542, in get_root_group
    return self.db.root_group
  File "/usr/lib/python3.7/site-packages/pykeepass/pykeepass.py", line 112, in root_group
    return self.find_groups(path='', first=True)
  File "/usr/lib/python3.7/site-packages/pykeepass/pykeepass.py", line 226, in find_groups
    res = self._find(prefix, group_xp, path=path, tree=group, **kwargs)
  File "/usr/lib/python3.7/site-packages/pykeepass/pykeepass.py", line 216, in _find
    **kwargs
  File "/usr/lib/python3.7/site-packages/pykeepass/pykeepass.py", line 141, in _xpath
    tree = self.tree
  File "/usr/lib/python3.7/site-packages/pykeepass/pykeepass.py", line 108, in tree
    return self.kdbx.body.payload.xml
AttributeError: 'NoneType' object has no attribute 'payload'

Local variables in innermost frame:
self: <pykeepass.pykeepass.PyKeePass object at 0x7fd6d5215050>