Cannot read property 'x' of undefined: Assertions are triggered in Micro View

[veillette]

While running sugar and salt solution (Macro Tab) with assertions enabled and fuzzMouse, it takes a few seconds before getting the following error.

Particle.js:24 Uncaught TypeError: Cannot read property 'x' of undefined
    at OpenSite.Particle [as constructor] (Particle.js:24)
    at new OpenSite (OpenSite.js:29)
    at Crystal.js:162
    at u (lodash-4.17.4.min.js:5)
    at Function.ru (lodash-4.17.4.min.js:67)
    at Crystal.js:156
    at Array.forEach (<anonymous>)
    at ItemList.forEach (ObservableArray.js:301)
    at SodiumChlorideCrystal.getOpenSites (Crystal.js:155)
    at Crystal.js:131

[veillette]

Moving the salt shaker in Micro view triggers the assertion.

[phet-steele]

I see both the above error and the one below when shaking the salt shaker:

CrystalMakerCanvasNode.js?bust=1525103252215:63 Uncaught TypeError: Cannot read property 'get' of undefined
    at drawCrystals (CrystalMakerCanvasNode.js?bust=1525103252215:63)
    at CrystalMakerCanvasNode.paintCanvas (CrystalMakerCanvasNode.js?bust=1525103252215:98)
    at CanvasNodeDrawable.paintCanvas (CanvasNodeDrawable.js?bust=1525103252215:86)
    at CanvasBlock.renderDrawable (CanvasBlock.js?bust=1525103252215:328)
    at CanvasBlock.update (CanvasBlock.js?bust=1525103252215:156)
    at BackboneDrawable.update (BackboneDrawable.js?bust=1525103252215:248)
    at DOMBlock.update (DOMBlock.js?bust=1525103252215:55)
    at BackboneDrawable.update (BackboneDrawable.js?bust=1525103252215:248)
    at Display.updateDisplay (Display.js?bust=1525103252215:434)
    at Sim.stepSimulation (Sim.js?bust=1525103252215:879)

[KatieWoe]

Closing for phetsims/qa#832 as CT does not track this sim. If this is in error, please reopen.