Can't freaking mount

[Zaphear]

SO FREAKING ANNOYING.. the saddle icon pops up over my horse but nothing happens when I click it. I've tried rebooting/restarting..are you just suppose to click the horse when the saddle icon pops up and then you mount it? Because nothing ♥♥♥♥♥♥♥ happens when I click, or try different buttons......