I am getting TypeError: ‘GeometryCollection’ object is not subscriptable when using plot_single_map function

Cartopy and Matplotlib can generate some issue, expecially when plotting masked data. If you are using the plot_single_map function and you are getting this error, you can try to set the transform_first kwarg to True in the plot_single_map function. This will transform the data to the target projection before plotting the contour, and it may solve the issue. Alternatively, you can try to set the contour arg to False and enable the pcolor plot, which may solve the issue as well.