Automation tool error during html5 export

Hey, I’m trying to export a car game to html5. I built the game in version 4.8

after converting the project to 4.9 i get an automation tool error, looking at the logs i find the following error:

2015.08.04-10.52.47:836][ 0]LogInit:Display: Warning/Error Summary
[2015.08.04-10.52.47:836][ 0]LogInit:Display: ---------------------
[2015.08.04-10.52.47:836][ 0]LogInit:Display: LogProperty:Error: UStructProperty::Serialize Loading: Property ‘StructProperty /Game/QCity/Tesla/TeslaAnimBlueprint.TeslaAnimBlueprint_C:AnimGraphNode_RotationMultiplier_F561330E4F5271658B0E8D869BC681B5’. Unknown structure.

Seams like a problem in the animation blueprint. is this a bug in the preview version, or do i need to change anything in my project ?

attaching the full log here.