[...]site-packages/dash/_validate.py", line 22, in validate_callback_args
raise exceptions.IncorrectTypeException(
dash.exceptions.IncorrectTypeException: The input argument `btn.n_clicks` must be a list or tuple of
`dash.dependencies.Input`s.
The callback decorator looks fine the Output, Input and State are correctly written too, what about the function? Their is 1 input and 2 states in your callback so your function definition should also have the same number of parameters.
Like this:
as i said, with the square brackets it works perfectly fine.
thanks for the debugging advice, but i am fine with how it is now. just in case somebody has the same problem he might stumble upon this post here and hopefully it helps him/her!