Show/hide layer problem: Cannot read property 'imagery' of undefined

Whenever I update the visibility of my layers, I am occasionally getting the following error which effectively kills my globe. Does anyone have any tips on troubleshooting this error? I am having trouble determining exactly what is causing it as it doesn’t happen all the time. I am on Cesium 1.1. Thanks!

TypeError: Cannot read property ‘imagery’ of undefined

at ImageryLayer._createTileImagerySkeletons (Cesium.js:111978)

at Cesium.js:113126

at QuadtreePrimitive.forEachLoadedTile (Cesium.js:114694)

at GlobeSurfaceTileProvider._onLayerAdded (Cesium.js:113125)

at GlobeSurfaceTileProvider._onLayerShownOrHidden (Cesium.js:113177)

at Event.raiseEvent (Cesium.js:4409)

at ImageryLayerCollection._update (Cesium.js:114055)

at GlobeSurfaceTileProvider.beginUpdate (Cesium.js:112792)

at QuadtreePrimitive.update (Cesium.js:114722)

at Globe.update (Cesium.js:115953)

That’s a bug that was fixed in Cesium 1.3, per this thread:!topic/cesium-dev/DuCm67uiy6A

Upgrading should resolve it.

Sweet. Moving to 1.2 seems to fix it for me. Thanks!

That thread references a fix in 1.3 then later says it was actually fixed in 1.2.