'other' must be an instance of matplotlib.axes._base._AxesBase, not a str

This error message is indicating that you are trying to pass a string ('other') as an argument where an instance of the class `matplotlib.axes._base._AxesBase` is expected.

You should check the code where you are passing the argument `other` and make sure that it is an instance of `matplotlib.axes._base._AxesBase`. If it is not, you will need to modify your code to create an instance of this class and pass it as the argument instead of the string.