| Previous | Next |
| MILEFFECTSERR_EFFECTHASNOCHILDREN | MILEFFECTSERR_NOTAFFINETRANSFORM |
MILEFFECTSERR_ALREADYATTACHEDTOLISTENER
The scope of MILEFFECTSERR_ALREADYATTACHEDTOLISTENER is MIL effect child collections and listeners. A graph or effect object is already attached to the listener the caller is trying to register. Keep 0x88980618 beside the returning method because a wrapper can replace this distinction with a generic subsystem message.
Do not hide the original condition
This is not proof that event delivery is broken; it prevents duplicate attachment to an already associated listener. Do not catch the HRESULT and continue rendering with a partially connected graph; later failures can obscure the invariant that was first violated.
Subsystem context
Composite effects and graph listeners have collection lifetimes independent of visual appearance. An empty child set can invalidate an operation that expects aggregation, while registering the same listener twice creates duplicate ownership of notifications. Both cases require inspecting collection membership and subscription state rather than pixel output.
Listener registration lifetime and duplicate subscription.
Evidence to preserve
- Effect instance and owning graph or group identity
- Connector, input, child, listener, property, or transform involved
- Calculated input and output bounds
- Construction sequence and first method returning the HRESULT
Isolation procedure
Test one child or one listener registration, then add and remove entries while logging object identity. Include an empty collection and a duplicate registration as explicit negative controls.
- Track registration tokens and detach before attaching a different lifetime.
- Rebuild the smallest graph containing only the implicated node and one known input.
- Log ownership changes and graph generation numbers.
- Validate the graph before allocating large intermediate resources.
Technical references
Looking for a different code? Search another status or error code.