Timelines Access None Error

Build Type: Binary

Build Version: 4.13.0-3106830+++UE4+Release-4.13


Not sure if this is considered a bug or it’s working as expected but here goes.

If I call a timeline from within a function and there is no ‘get’ variable node for that timeline somewhere in the main ‘Event Graph’, when the function is called I get an accessed none error in the log:

LogScript:Warning: Accessed None trying to read property Timeline_test
TimelineTest_C /Game/ThirdPersonBP/Maps/UEDPIE_0_ThirdPersonExampleMap.ThirdPersonExampleMap:PersistentLevel.TimelineTest_49
Function /Game/ThirdPersonBP/TimelineTest.TimelineTest_C:TestTimeLine:000D
PIE:Error: Error Blueprint Runtime Error: Accessed None trying to read property Timeline_test from function: ‘TestTimeLine’ from node: Play from Start in graph: TestTimeLine in object: TimelineTest with description: Accessed None trying to read property Timeline_test


With a new project I’ve created a simple actor called ‘TimeLineTest’ that calls a function to play a timeline called ‘TimeLine_Test’. The actor is then placed in the level.

In the ‘TimeLineTest’ actor I’ve created a simple key press in the ‘event graph’ that calls a simple function, the function itself tells the time line to start playing.

Playing the game if you press the input to trigger the ‘TestTimeLine’ function you get the accessed none error.


Placing a get reference and then connecting to it another timeline node in the main ‘event graph’ fixes the problem. The odd thing is it doesn’t even need to be linked up to any other nodes, it can just sit there doing nothing.

Here’s the updated event graph with the fix:

and here’s in game running the function and it working.

Can confirm this bug. Opened up my project this morning and all my timelines suddenly weren’t working. Attached them to a non executed node and they are all fixed again. Weird bug, but thanks for posting the workaround!

I’m also seeing this bug, but it is not resolved by your solution. I’m using the Play from Start node, if this makes any difference.

A better workaround is to use an event in the main graph instead, just call the event from your function and hook up the new event to the ‘play/play from start’ pin in the main event graph.

not sure if its a bug or that we were just using timelines in a different way than expected by the devs :slight_smile:

guess the timeline variable never gets initialized when its running from inside a function for some reason.