CZML with polyline using references

Using Cesium 1.3

I am trying to render a set of points that move over time using CZML with some polylines using references to those points to show connections. When a point reaches the end of it's interval I get the following error.

DeveloperError: cartesian is required. DeveloperError@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:1282:19 Ellipsoid.prototype.scaleToGeodeticSurface@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:4074:1 Ellipsoid.prototype.cartesianToCartographic@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:4007:17 PolylinePipeline.generateArc@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:32690:21 PolylinePipeline.generateCartesianArc@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:32718:27 DynamicGeometryUpdater.prototype.update@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:90015:25 DynamicGeometryBatch.prototype.update@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:79603:13 GeometryVisualizer.prototype.update@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:79760:21 DataSourceDisplay.prototype.update@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:91396:26 Viewer/<@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:136587:29 Event.prototype.raiseEvent@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:4396:17 Clock.prototype.tick@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:29787:9 CesiumWidget.prototype.render@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:132527:27 render@http://localhost:8080/libs/cesium-1.3/Build/CesiumUnminified/Cesium.js:132001:25

I am assuming this is because the polyline no longer has a coordinate available from the point it was using before. Is there an easy workaround for this?

CZML Sample :

[{"id":"document","version":"1.0"},{"id":"ga.a","polyline":{"positions":{"references":["ga#position","a#position"]},"material":{"solidColor":{"rgba":[255,255,255,255]}}},"startTime":1414763306755,"endTime":1414763366755,"show":[{"interval":"2014-10-31T13:48:26.755Z","boolean":true},{"interval":"2014-10-31T13:49:26.754Z","boolean":false}]},{"id":"gb.b","polyline":{"positions":{"references":["gb#position","b#position"]},"material":{"solidColor":{"rgba":[255,255,255,255]}}},"startTime":1414763306755,"endTime":1414763466755,"show":[{"interval":"2014-10-31T13:48:26.755Z","boolean":true},{"interval":"2014-10-31T13:51:06.754Z","boolean":false}]},{"id":"ga","show":true,"position":{"cartographicDegrees":["2014-10-31T13:49:26.755Z",2.2,2,2,"2014-10-31T13:48:56.755Z",1.2,1,1,"2014-10-31T13:48:26.755Z",0.2,0,0]},"point":{"color":{"rgba":[41,128,185,255]},"pixelSize":10},"startTime":1414763306755,"endTime":1414763366755,"availability":"2014-10-31T13:48:26.755Z/2014-10-31T13:49:26.755Z"},{"id":"gb","show":true,"position":{"cartographicDegrees":["2014-10-31T13:48:56.755Z",1.2,5.1,1,"2014-10-31T13:48:26.755Z",0.2,4.1,0,"2014-10-31T13:51:06.755Z",2.2,6.1,2]},"point":{"color":{"rgba":[41,128,185,255]},"pixelSize":10},"startTime":1414763306755,"endTime":1414763466755,"availability":"2014-10-31T13:48:26.755Z/2014-10-31T13:51:06.755Z"},{"id":"a","show":true,"position":{"cartographicDegrees":["2014-10-31T13:48:56.755Z",1.2,1.2,100,"2014-10-31T13:48:26.755Z",0.2,0.2,100,"2014-10-31T13:49:26.755Z",2.2,2.2,100]},"point":{"color":{"rgba":[241,196,15,255]},"pixelSize":10},"startTime":1414763306755,"endTime":1414763366755,"availability":"2014-10-31T13:48:26.755Z/2014-10-31T13:49:26.755Z"},{"id":"b","show":true,"position":{"cartographicDegrees":["2014-10-31T13:48:26.755Z",0.2,4,100,"2014-10-31T13:51:06.755Z",2.2,6,100,"2014-10-31T13:48:56.755Z",1.2,5,100]},"point":{"color":{"rgba":[241,196,15,255]},"pixelSize":10},"startTime":1414763306755,"endTime":1414763466755,"availability":"2014-10-31T13:48:26.755Z/2014-10-31T13:51:06.755Z"}]

Juan