Why can't I change the default animations in Online mode?

Recently, I have made a StarterCharacter that looks rather different from the default ROBLOX character. So, I've managed to animate it with the animation plugin, and upload the animations, etc.

-What I've done is used the default animation script, and replaced the default animations with the custom animations I made. However, in Play Solo, the animations work fine. But, in online mode ( or in the server play ), the animations refuse to load onto the player.

I've tried loading these animations onto NPCs, which works fine on them in online mode.

• I've also tried modifying the original Animate script in a script that assigns them animations, works in Play Solo, but not in Online mode.

Here's the script who assigns the animations.

local Animator = player.Character:FindFirstChild("Animator")
        Animate.idle.Animation1.AnimationId = 'http://www.roblox.com/asset/?id=684287672'
        Animate.idle.Animation2.AnimationId = 'http://www.roblox.com/asset/?id=684292381'
        Animate.run.RunAnim.AnimationId = 'http://www.roblox.com/asset/?id=684271786'
        Animate.walk.WalkAnim.AnimationId = 'http://www.roblox.com/asset/?id=684271786'
        Animate.jump.JumpAnim.AnimationId = 'http://www.roblox.com/asset/?id=684293328'

If there are any specifications that you may need or any answers, please let me know!