Hi Chris,

I understand that Unity 6000.6 may not have been officially tested or supported by Adventure Creator yet, but we tried upgrading our project and found a small compatibility issue that I wanted to report early.

Environment:

• Adventure Creator 1.86.5
• Unity 6000.6.0f1
• macOS / Apple Silicon

After opening the project in Unity 6000.6, compilation failed with these two errors:

Assets/AdventureCreator/Scripts/ActionList/Editor/HierarchyIcons.cs(165,24):
error CS0619: 'EntityId.implicit operator EntityId(int)' is obsolete:
'EntityId will not be representable by an int in the future.
This casting operator will be removed in a future version.'

Assets/AdventureCreator/Scripts/ActionList/Editor/HierarchyIcons.cs(187,22):
error CS0619: 'EntityId.implicit operator EntityId(int)' is obsolete:
'EntityId will not be representable by an int in the future.
This casting operator will be removed in a future version.'

Under UNITY_6000_5_OR_NEWER, actionListIDs and rememberIDs are declared as:

HashSet<EntityId>

However, GatherIDs() still adds values returned by:

UnityVersionHandler.GetInstanceID(gameObject)

This returns an int, so the code relies on the implicit int -> EntityId conversion. In Unity 6000.6 that conversion is now marked as an error instead of a warning.

We fixed it by using GameObject.GetEntityId() directly for Unity 6000.5 and newer, while keeping the existing path for older Unity versions:

#if UNITY_6000_5_OR_NEWER
    actionListIDs.Add(actionList.gameObject.GetEntityId());
#else
    actionListIDs.Add(UnityVersionHandler.GetInstanceID(actionList.gameObject));
#endif

And similarly for rememberIDs:

#if UNITY_6000_5_OR_NEWER
    rememberIDs.Add(constantID.gameObject.GetEntityId());
#else
    rememberIDs.Add(UnityVersionHandler.GetInstanceID(constantID.gameObject));
#endif

This is also consistent with the existing comparisons later in HierarchyItemCB(), which already use gameObject.GetEntityId() under UNITY_6000_5_OR_NEWER.

After applying these two changes, the Adventure Creator-related compilation errors were resolved successfully in Unity 6000.6.0f1.

I hope this compatibility fix can be included in a future Adventure Creator update.

Thanks!