TX 3D Builder open beta bug: error when importing asset

When trying to add an asset get the following error:

Error:
{"Index was outside the bounds of the array."}
Data:
{System.Collections.ListDictionaryInternal}
Source:
"TorqueBuilderCore"

Stack Trace:
" at GarageGames.Torque.TS.ShapeInstance._RenderMesh(ObjectInstance& obj, Int32 objectDetail, Material[] materialList, SceneRenderState srs)\r\n at GarageGames.Torque.TS.ShapeInstance.Render(Int32 dl, Single intraDL, Vector3 objectScale, SceneRenderState srs, Int32 hidden)\r\n at GarageGames.Torque.T3D.T3DTSRenderComponent.Render(SceneRenderState sceneRenderState)\r\n at GarageGames.Torque.T3D.T3DSceneComponent.Render(SceneRenderState sceneRenderState)\r\n at GarageGames.Torque.T3D.T3DSceneGraph._RenderObjects(TorqueObjectType renderMask, Single aspectRatio)\r\n at GarageGames.Torque.SceneGraph.BaseSceneGraph.PreRender(GFXDevice gfx, TorqueObjectType renderMask, TorqueObjectType noRenderMask, Single aspectRatio)\r\n at GarageGames.Torque.GUI.GUISceneview.OnRender(Vector2 offset, RectangleF updateRect)\r\n at GarageGames.Torque.GUI.GUICanvas.OnRender(Vector2 offset, RectangleF updateRect)\r\n at GarageGames.Torque.GUI.GUICanvas.RenderFrame()\r\n at GarageGames.Torque.XNA.TorqueEngineComponent.Draw(GameTime gameTime)\r\n at Microsoft.Xna.Framework.Game.Draw(GameTime gameTime)\r\n at GarageGames.Torque.GameUtil.TorqueGame.Draw(GameTime gameTime)\r\n at TorqueXBuilder3D.TorqueXBuilderGame.Draw(GameTime gameTime)\r\n at Microsoft.Xna.Framework.Game.DrawFrame()\r\n at Microsoft.Xna.Framework.Game.Tick()\r\n at Microsoft.Xna.Framework.Game.HostIdle(Object sender, EventArgs e)\r\n at Microsoft.Xna.Framework.GameHost.OnIdle()\r\n at Microsoft.Xna.Framework.WindowsGameHost.ApplicationIdle(Object sender, EventArgs e)\r\n at System.Windows.Forms.Application.ThreadContext.System.Windows.Forms.UnsafeNativeMethods.IMsoComponent.FDoIdle(Int32 grfidlef)\r\n at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)\r\n at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)\r\n at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)\r\n at System.Windows.Forms.Application.Run(Form mainForm)\r\n at Microsoft.Xna.Framework.WindowsGameHost.Run()\r\n at Microsoft.Xna.Framework.Game.Run()\r\n at TorqueXBuilder3D.TorqueXBuilderGame.Main()"