Ok so im making a custom character and im adding animations into it but when i test the game the output gives me this error 
Failed to load animation - sanitized ID: rbxassetid://4730823780
this is my script
There’s nothing wrong with your script, I’ve been experiencing this error as well. So have many other scripters. It think it’s just a studio bug, I’m currently looking into what it is and how to fix it.
Doesn’t the script just play once, meaning that the animation will only play once after checking the player’s speed?
no because the animation its looped
That still doesnt mean its going to play in the first place. But anyways I see that the animation sometimes does not load in, maybe try make it again
This should work?
local character = script.Parent
local humanoid = character:WaitForChild(“Humanoid”)
local walkAnim = script:WaitForChild(“Walk”)
local walkAnimTrack = humanoid.Animator:LoadAnimation(walkAnim)
humanoid.Running:Connect(function(speed)
if speed > 0 then
if not walkAnimTrack.IsPlaying then
walkAnimTrack:Play()
end
else
if walkAnimTrack.IsPlaying then
walkAnimTrack:Stop()
end
end
end)
It probably should, but did you make the animation. Im just wondering if roblox allows you to use other peoples animation and is the ID animation correct?
Its a custom character That means I cant use roblox animations so yeah i made my own animation and published it
try removing the “.Animator” after the humanoid
local walkAnimTrack = humanoid.Animator:LoadAnimation(walkAnim)
I restarted Studio and now it works
but it plays for ever
maybe its because the hip weight?
It works now I just changed he hip weight to 2
noiceee all it took was just a restart 
`
Yes lol They should fix this glitch
it probably could also be your studio not connecting to the marketplace properly, maybe lag idk