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Unity Timeline Not Playing - Animation Sequencing Fix

Problem: Unity Timeline does not play when you enter Play mode or trigger it at runtime. The Timeline window may show the correct clips, but nothing happens in the Game view: no animation, no camera switch, no activation. Sometimes the Timeline plays in the editor but not in a build.

Root cause: Timeline not playing usually comes from one of these: the Playable Director is missing, disabled, or not set to play on awake; the Timeline asset is not assigned or the wrong one is assigned; bindings (Animation Track, Activation Track, etc.) are missing or point to the wrong object; weight or blend settings prevent visible output; or runtime code is not triggering the director when you expect. Fixing it means checking the director, asset, bindings, and trigger logic in order.

This guide walks you through the most common fixes step by step. Apply them in order; many issues are resolved by ensuring the Playable Director is set up and the correct Timeline is bound.

Quick fix checklist

  1. Playable Director – The GameObject with the Playable Director component must have the correct Playable (Timeline asset) assigned and Play On Awake set as needed.
  2. Bindings – Every track (Animation, Activation, Control) must be bound to a valid object in the scene; red or missing bindings mean no output.
  3. Activation and weight – Activation tracks must target the right objects; animation tracks should have sufficient weight and no conflicting layers.
  4. Runtime – If you start playback from code, call PlayableDirector.Play() after the director and bindings are ready.

Solution 1: Check Playable Director and Timeline Asset

Problem: The director has no Timeline asset, the wrong one is assigned, or it is disabled so Timeline never plays.

Step 1: Select the GameObject that should run the Timeline

  • In the Hierarchy, find the object that has the Playable Director component (often the same as the one with the Timeline asset in the scene).
  • If you do not see a Playable Director, the Timeline cannot play; add one via Add Component → Playables → Playable Director.

Step 2: Assign the Timeline asset

  • In the Playable Director component, check the Playable field.
  • It must reference the Timeline asset (the .playable file) you edited in the Timeline window.
  • Drag the correct Timeline asset from the Project into Playable, or use the circle selector to choose it.

Step 3: Set Play On Awake

  • If the Timeline should play as soon as the scene (or that object) loads, enable Play On Awake.
  • If you trigger it from script, leave Play On Awake off and call PlayableDirector.Play() when needed.

Step 4: Confirm Update Method (optional)

  • Director Update Mode (e.g. Game Time, Unscaled Game Time) affects when the timeline advances. For most gameplay and cutscenes, Game Time is correct.

Verification: Enter Play mode with Play On Awake on; the Timeline should start. If it still does not play, move to Solution 2.

Solution 2: Fix Missing or Broken Bindings

Problem: Tracks in the Timeline have no binding or the wrong binding, so clips do not drive any object.

Step 1: Open the Timeline and the binding list

  • Select the GameObject with the Playable Director and open Window → Sequencing → Timeline.
  • In the Timeline window, look at the left column: each track shows its binding (the object it controls).

Step 2: Bind Animation Tracks

  • For each Animation Track, the binding must be the Animator (or legacy Animation component) you want to drive.
  • If the binding is None or a red/missing reference, drag the correct GameObject (with Animator) from the Hierarchy onto the track header, or use the track’s binding field to assign it.
  • The Avatar and Animator must be compatible with the clips (e.g. humanoid vs generic).

Step 3: Bind Activation Tracks

  • Activation Tracks control GameObject.SetActive. The binding must be the GameObject you want to turn on or off.
  • Assign the correct GameObject to the Activation Track if it is missing or wrong.

Step 4: Bind Control Tracks

  • Control Tracks (e.g. for prefab instantiation or sub-Timelines) need the correct target.
  • Ensure Control clips reference valid prefabs or Playable Directors.

Step 5: Rebind after scene/prefab changes

  • If you duplicated a scene or prefab, bindings can point to old instances. Reassign each track to the objects in the current scene.

Verification: With correct bindings, entering Play mode (and Play On Awake on) should show animation, activation, or control behavior. If Timeline still does not play, check Solution 3.

Solution 3: Activation, Weight, and Layer Conflicts

Problem: Tracks are bound but something overrides or blocks the result (activation off, weight zero, or another Animator layer taking over).

Step 1: Check Activation Track clips

  • If you use an Activation Track to enable the character or camera, ensure the clip is on at the time you expect (clip start/end).
  • If the binding is wrong, the target object never activates; fix bindings as in Solution 2.

Step 2: Check Animation Track weight

  • Animation clips on a track can have weight or be blended. If the effective weight is 0 or the track is muted, you see no motion.
  • In the Timeline, ensure clips are not muted and the track is not disabled.
  • If using Animation Layer blending in the Animator, ensure the Timeline-driven layer has sufficient weight (e.g. layer weight 1 when the Timeline is playing).

Step 3: Resolve Animator conflicts

  • If another script or state machine sets the same Animator state or layer weight, it can override the Timeline.
  • Temporarily disable other animation logic and test; then reintroduce and adjust order or weights so the Timeline can drive when intended.

Verification: Timeline should now drive animation and activation as designed. If it only fails in a build, see Solution 4.

Solution 4: Timeline Plays in Editor but Not in Build

Problem: Timeline works in the editor but does not play in a built game.

Step 1: Ensure the Timeline asset and director are in the build

  • The scene that contains the Playable Director (and the Timeline asset reference) must be included in Build Settings.
  • If the Timeline is only in a scene that is never loaded, it will never run in the build.

Step 2: Check runtime script references

  • If you start the Timeline from code (e.g. PlayableDirector.Play()), the reference to the PlayableDirector must be valid at runtime (e.g. assigned in the inspector or found by name/tag).
  • Avoid relying on editor-only state; test with a development build if needed.

Step 3: Check execution order

  • If you call Play() from script, ensure the director and its bindings are initialized (e.g. call after the scene has loaded and objects are active).

Verification: Run a build and trigger the Timeline; it should play. If it still does not, double-check that the correct scene is loaded and the director and bindings are the same as in the editor.

Solution 5: Trigger Timeline from Script Correctly

Problem: You start the Timeline with code but nothing happens.

Step 1: Get a valid reference to PlayableDirector

  • Use GetComponent<PlayableDirector>() on the same GameObject, or assign the director in the inspector.
  • Ensure the GameObject is active so the component is enabled.

Step 2: Call Play at the right time

  • Call playableDirector.Play() when you want playback to start.
  • Optionally use playableDirector.Play(playableDirector.playableAsset) to force the current asset.
  • To play from a specific time, set playableDirector.time then call Play().

Step 3: Use stopped/played callbacks if needed

  • Subscribe to playableDirector.stopped or playableDirector.played to chain logic (e.g. load next scene when Timeline finishes).

Verification: Trigger the script (e.g. button, trigger zone); the Timeline should play. If not, confirm the director and Playable asset are correct and bindings are valid.

Prevention tips

  • One director per Timeline – Keep a clear mapping: one Playable Director component, one Timeline asset.
  • Rebind after copy – When duplicating scenes or prefabs, re-check every track binding.
  • Name key objects – Name the director GameObject and main bindings so they are easy to find when fixing missing references.
  • Test in build – Periodically test Timeline in a development build to catch build-only issues early.

Related issues and links

Summary

Unity Timeline not playing is usually fixed by: (1) ensuring the Playable Director has the correct Timeline asset and Play On Awake (or a scripted Play()), (2) binding every track to the right object (Animator, GameObject, etc.), (3) checking activation and animation weight so output is visible, and (4) in builds, confirming the scene and references are included and triggered at the right time. Work through the solutions in order and verify after each step.

Bookmark this page for quick reference. If you are still stuck, check the Unity Timeline documentation for your Unity version.