Hey everyone!
I was trying to load a custom run animation for my players characters.
After some research I found that using the HumanoidDescription System would be the best way.
I’m using this code based off of the article above.
It should work, but for some reason I get this error:
Anyone know the problemo?
Did you do the animation on an R6 or R15 rig?
I animated a r15 rig. I also did make sure to set the animation priority to movement.
Are the characters in your game R15?
Yes. It is indeed a R15 game. I don’t know if the problem is as simple as a rigging issue. It might have something to do with the HumanoidDescription System.
The animation should be an animation instance with the animation id.
Then all you’ll have to do to play the animation from here on is to commit :LoadAnimation() into the Humanoid and commit :Play(). 
Useful API resources:
What this have to do with HumanoidDescription animation setting? The person asking the original post did not ask on how to run an animation?
I checked the wiki and it should be correct, try downloading the file it gives then test if it works (they give you an example file on the wiki page).
The humanoid description system uses catalog IDs which are not animation IDs, but instead point to models containing the animation instances. You cannot use it in combination with actual animation IDs.
OP has to adapt the script to replace the animation instances instead.
Guess you’re right then, there is otherwise a way to play an animation as default for running by editing the Animation script at least as a solution for the original post.
The asset you provided, which I am guessing isn’t an animation asset, to apply a humanoid description it has to be an asset like this: Robot Run - Roblox
If you want a custom run animation I suggest editing the animation module and placing it into the starter character.
I tried forking the animate script already. It works fine, except I had some replication issues.
The character just walked around frozen on the server.
Have you tried going to the Humanoid Animation Script and putting in your Run Animation ID into the current ID.
This probably isn’t needed but you would usually do 'rbxassetid://IDNUMBER' or 'rbxasset://IDNUMBER' one of them works I know that, maybe try those? I don’t usually use the straight up number, also make sure your users are R15 in-game because humanoid:ApplyDescription has only worked with R15 for me in the past.
I already have tried this, and it unfortunately doesn’t solve the issue.
By humanoid animation script do you mean the “animate” localscript inside of the character?
I don’t believe there is a humanoid animation script.
Instead of using descriptionClone, have you used LoadAnimation instead and just macro the W,A,S,D keys for animation?
I might have been wrong I’ll try fix it ( sorry im really new to scripting)
What do you mean exactly? Do you mean whenever the player presses one of those keys play the animation?
Or holds them, yes, that’s what I mean. I use that a lot if this doesn’t work, which it usually doesn’t.
Ok. Thank you very much 
. I will try this and get back to you. I was hoping for a simpler solution, but it seems I will have to resort to this.
