rectangular sensor error in Cesium 1.20

I’m using the cesium-sensor plugin and have conic sensors working, but I’m getting an error when attempting to use agi_rectangularSensor. If I comment out the rectangular sensor property or replace it with a similar conic sensor version, it works fine. Any suggestions?

Here’s the czml snippet:
{{
“id”: “rect_sensor”,

“position”: {

“reference”: “satellite#position”

},

“orientation”: {

“reference”: “satellite#orientation”

},

“agi_rectangularSensor”: {

“show”: true,

“intersectionColor”: {

“rgba”: [

0,

255,

255,

255

]

},

“intersectionWidth”: 2,

“radius”: 84328000,

“xHalfAngle”: 0.174533,

“yHalfAngle”: 0.349066,

“lateralSurfaceMaterial”: {

“solidColor”: {

“color”: {

“rgba”: [

0,

255,

255,

51

]

}

}

}

}

}}

``

And here’s the error:

An error occurred while rendering. Rendering has stopped.

TypeError: Cannot read property ‘mode’ of undefined

TypeError: Cannot read property ‘mode’ of undefined

at CustomSensorVolume.update (http://localhost:3579/js/cesium-sensors/CesiumSensors.js:1005:27)

at RectangularPyramidSensorVolume.update (http://localhost:3579/js/cesium-sensors/CesiumSensors.js:2148:28)

at a.update (http://localhost:3579/js/Cesium-1.20/Cesium.js:466:10219)

at Ne (http://localhost:3579/js/Cesium-1.20/Cesium.js:468:11725)

at Re (http://localhost:3579/js/Cesium-1.20/Cesium.js:468:11020)

at Me (http://localhost:3579/js/Cesium-1.20/Cesium.js:468:9726)

at ke (http://localhost:3579/js/Cesium-1.20/Cesium.js:468:14241)

at ue.render (http://localhost:3579/js/Cesium-1.20/Cesium.js:468:19250)

at A.render (http://localhost:3579/js/Cesium-1.20/Cesium.js:473:31394)

at t (http://localhost:3579/js/Cesium-1.20/Cesium.js:473:18136)