Here I'll post the log, but it essentially looks like it tries to mount, and in game it does nothing, not even the animation. Is the paladin horse just bugged?

17_Feb_2018_03H18.log.html

Hello, try to put 

Summon Thalassian Warhorse

 

instead 

Thalassian Warhorse

 

Nah this time it says mount does not exist

Edit: It said mount does not exist once I believe, but now it does the same thing as before, only "[Mount] Mounting ground mount Summon Thalassian Warhorse," and it essentially makes me try to cast it after every distance I have set on Mount Distance. It also occasionally says "[Mount] Mounting failed"

Summon Warhorse

actually works for me, thanks for steps into right direction haha