This minimal example throws an error (without crashing) when

1. the slider is initialized with a slidermin/slidermax value
2. the slider is moved with the mouse
   (the program does not crash, but the slider also does not respond)

Minimal example:

import matplotlib.pyplot as plt
from matplotlib.widgets import Slider

fig, ax = plt.subplots()
slider = Slider(ax=ax, label='', valmin=0.0, valmax=24.0, valinit=15.0,
                slidermin=10.0, slidermax=20.0)
plt.show()

Fix follows.