List of steps to reproduce:

input_list_choice('Frage?', ['foo', 'bar', None])
1: foo
2: bar
3: None
Frage?:
5

What happens?:
5 is an invalid response but the error message
pywikibot.error('Invalid response')
is not printed

What should have happened instead?:
Invalid response should be shown

The reason may be introduced with cached output functionaliy and the default output funtions are locked during input