Animation Events Not Clearing in Unity with Spine 4.2 Runtime

AHAKuo

Hi Spine Team,

I'm using Spine 4.2 (4.2.43) with the Spine-Unity 4.2 runtime (spine-unity-4.2-2025-08-07.unitypackage) and encountering an issue where animation events are not cleared in Unity after being removed in Spine.

Steps to Reproduce:

In Spine 4.2, create an event named "AnimationEvent" with the value "test" and place it on an animation.
Export the animation to Unity.
Verify the event appears in Unity's AnimationClip.
In Spine, remove the "AnimationEvent" event from the animation.
Re-export to Unity.
Check the AnimationClip in Unity—the event with value "test" still exists.

Observation:
The issue seems related to the fix in commit edea4bef, where events with the value "SpineEvent" are cleared, but others (like "test") persist. I discussed this before in forum post 25327 (https://en.esotericsoftware.com/forum/d/25327-spine-unity-runtime-not-clearing-old-events).

Can you confirm if this is a known issue in the 4.2 runtime and suggest a fix or workaround? Thanks!

EDIT: EsotericSoftware/spine-runtimes1838

I looked at the ticket, and it seems that user events aren't properly cleared.

Spinebot

The issue you're experiencing with animation events not clearing in Unity after being removed in Spine seems to be related to how the Spine-Unity runtime handles events. In the past, there was a fix implemented to ensure that events with the string parameter "SpineEvent" are cleared upon re-import, but user-added events or those without this parameter might persist. This behavior was addressed in earlier versions, as noted in the forum post you mentioned.

To resolve this, ensure that you are using the latest version of the Spine-Unity runtime, as updates often include bug fixes and improvements. If the issue persists, a potential workaround is to manually clear the events in Unity's AnimationClip after re-importing from Spine. This can be done by accessing the AnimationClip in Unity and removing the unwanted events manually.

Harald

@AHAKuo This is a known issue, and was mainly a limitation due to what the animation asset can store. We have however just pushed a fix for the issue by using the object reference value as fallback solution, which won't clash with user values either (we can't set int or float parameters to a sentinel value, as a value of 0 might be unser or a deliberately set value, read by user code).

A new spine-unity 4.2 unitypackage is available for download:
https://esotericsoftware.com/spine-unity-download
Please let us know if this resolves the issue on your end as well. Thanks for reporting.