I’m experiencing an intermittent issue with the new Ability System in UEFN where a custom item using custom firing animations will randomly stop activating its ability.
The item can work perfectly for a period of time, correctly triggering animations, firing events, and generating logs. However, without any change in player state or input, the ability will suddenly stop activating.
When this happens, the client appears to attempt activation, briefly starting the firing animation before immediately canceling it and returning to its original state. It almost looks like client-side prediction is occurring, but the activation is being rejected or canceled.
Steps to Reproduce:
- Create a custom item using the new UEFN Ability System.
- Configure the item with a custom firing ability and custom animations.
- Add logging to monitor successful ability activations.
- Equip the item and repeatedly press the fire input.
- Observe that the ability initially activates correctly, triggering animations, events, and logs.
- Continue firing while standing completely still, without performing any other actions.
- At seemingly random intervals, the ability may suddenly stop activating.
- Drop the item and pick it back up to temporarily restore normal functionality.
Expected Result:
The custom item’s ability should consistently activate whenever the player presses the fire input, assuming all activation requirements are met. Animations should play correctly, and all associated events and gameplay logic should execute.
Actual Result:
The ability randomly stops activating despite previously working correctly under identical conditions.
When the issue occurs:
- The client briefly starts the firing animation before immediately canceling it.
- The animation snaps back to its original state.
- Ability activation events stop firing.
- No logs are generated from the expected activation logic.
- Repeatedly pressing the fire input does not consistently resolve the issue.
- Dropping and re-equipping the item temporarily restores functionality.
Additional Observations:
One particularly unusual aspect is that the issue can begin while the player is completely stationary and doing nothing besides repeatedly firing. The ability can go from activating and logging successfully to suddenly doing nothing, without any noticeable change in circumstances.
The issue is completely intermittent and does not appear to occur after a specific number of activations.
The behavior resembles a possible mismatch between client-side ability prediction and server-side activation, although I have not confirmed this as the cause.
The fact that dropping and re-equipping the item temporarily resolves the issue may suggest that some internal ability or item state is being reset.
Impact:
This issue significantly affects the reliability of custom items using the new Ability System. Since activation can fail unpredictably during normal gameplay, it makes the item unreliable and difficult to use in a published experience.
Could the UEFN team investigate whether this is a known issue involving intermittent ability activation failures, client-server prediction, replication, or ability state becoming invalid until an item is re-equipped?
I’m happy to provide additional information, logs, or a reproduction project if needed.
Thank you!