Refine Mask is practically unusable.

Hi,

I've been having serious issues with the Refine Mask feature in Photoshop, i've attached a video below. I keep getting the message 'An integer between 0 and 100 is required. Closest value inserted.' when using any brushed or sliders in the settings.

Any help is greatly appreciated because Refine Mask is almost unusable, and it's something i use a lot.