if you want to fix this just replace
screenlets.show_error(self, 'Failed to add %sScreenlet.' % name)
with
screenlets.show_error(None, 'Failed to add %sScreenlet.' % name)
if you want to fix this just replace
screenlets. show_error( self, 'Failed to add %sScreenlet.' % name)
with
screenlets. show_error( None, 'Failed to add %sScreenlet.' % name)