FactoryException: Unknown class <QRCodeWidget>

[AndreMiras]

https://sentry.io/andre-5t/pywallet/issues/501681861/
On MacOS

FactoryException: Unknown class <QRCodeWidget>
(18 additional frame(s) were not displayed)
...
  File "kivy/lang/builder.py", line 585, in _apply_rule
    self._apply_rule(child, crule, rootrule)
  File "kivy/lang/builder.py", line 584, in _apply_rule
    self.apply(child)
  File "kivy/lang/builder.py", line 469, in apply
    self._apply_rule(widget, rule, rule, ignored_consts=ignored_consts)
  File "kivy/lang/builder.py", line 544, in _apply_rule
    cls = Factory_get(cname)
  File "kivy/factory.py", line 131, in __getattr__
    raise FactoryException('Unknown class <%s>' % name)

FactoryException: Unknown class <QRCodeWidget>