I havn’t been on here in a while so can’t remember if this is where I should be posting this. I did put it on answerhub but then I remembered that no one bothers with answerhub 
Build Type: Binary
Build Version: 4.13.0-3106830+++UE4+Release-4.13
Description:
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
Example:
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.
http://i1382.photobucket.com/albums/ah256/chris_donovan1/2_zpspakmjerd.png
Playing the game if you press the input to trigger the ‘TestTimeLine’ function you get the accessed none error.
http://i1382.photobucket.com/albums/ah256/chris_donovan1/3_zpsfmbrqeuq.png
Workaround:
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:
http://i1382.photobucket.com/albums/ah256/chris_donovan1/4_zps5svoyxso.png
and here’s in game running the function and it working.
http://i1382.photobucket.com/albums/ah256/chris_donovan1/5_zpsvo1htwyf.png
