when i morph into that custom character, both arm wont start the animation. other part work perfectly but the arm wont start the animation. All animation have this problem as well : Walk, Idle, Sit…
in Animation Editor, Idle Animation :

In Game , Idle Animation:

animate script inside the character:
local character = script.Parent
local humanoid = character:WaitForChild("Humanoid")
local walkAnim = script:WaitForChild("Walk")
local walkAnimTrack = humanoid.Animator:LoadAnimation(walkAnim)
local idleAnim = script:WaitForChild("Idle")
local idleAnimTrack = humanoid.Animator:LoadAnimation(idleAnim)
local sitAnim = script:WaitForChild("Sit")
local sitAnimTrack = humanoid.Animator:LoadAnimation(sitAnim)
local jumpAnim = script:WaitForChild("Jump")
local jumpAnimTrack = humanoid.Animator:LoadAnimation(jumpAnim)
local fallAnim = script:WaitForChild("Fall")
local fallAnimTrack = humanoid.Animator:LoadAnimation(fallAnim)
humanoid.Running:Connect(function(speed)
if speed > 0 then
if not walkAnimTrack.IsPlaying and idleAnimTrack.IsPlaying then
idleAnimTrack:Stop()
jumpAnimTrack:Stop()
walkAnimTrack:Play()
end
else
if walkAnimTrack.IsPlaying and not idleAnimTrack.IsPlaying then
idleAnimTrack:Play()
jumpAnimTrack:Stop()
walkAnimTrack:Stop()
end
end
end)
idleAnimTrack:Play()
humanoid.Seated:Connect(function(active)
if active == true then
sitAnimTrack:Play()
else
sitAnimTrack:Stop()
end
end)