Demo: https://codepen.io/mafar/pen/NWKOxzr?editors=0010
This pen is bare minimum for bug reproduction

Explaination: https://plot.ly/javascript/reference/#contour
Consider a user is given 3 inputs where he has to set

1. contours-start
2. contours-end
3. contours-size

and he types invalid option and plotly breaks

Required:
Instead of breaking, plotly must ignore values or throw warning

Image: wait to load