TypeError: n.remove is not a function

Hi folks

I added a wall to a project to replace a cylinder as I did not want a filled cylinder (with end caps). In this project the user can change the position of this cylinder/wall. When I was using a cylinder I was removing it and making a new one when the user wanted to move it. When I switched instead to using a wall I started getting this error when I try to remove/move the wall: Anyone got any ideas?

An error occurred while rendering. Rendering has stopped.

TypeError: n.remove is not a function
TypeError: n.remove is not a function
at c.remove (http://localhost:8080/Apps/wt3d/Cesium/Cesium.js:439:30063)
at c (http://localhost:8080/Apps/wt3d/Cesium/Cesium.js:439:31458)
at m.update (http://localhost:8080/Apps/wt3d/Cesium/Cesium.js:440:1536)
at T.update (http://localhost:8080/Apps/wt3d/Cesium/Cesium.js:444:10233)
at Z._onTick (http://localhost:8080/Apps/wt3d/Cesium/Cesium.js:464:18781)
at r.raiseEvent (http://localhost:8080/Apps/wt3d/Cesium/Cesium.js:417:22694)
at l.tick (http://localhost:8080/Apps/wt3d/Cesium/Cesium.js:423:12017)
at P.render (http://localhost:8080/Apps/wt3d/Cesium/Cesium.js:462:1888)
at t (http://localhost:8080/Apps/wt3d/Cesium/Cesium.js:461:21088)

I updated Cesium to the latest version and this problem seems to have gone away.