Grid Cell Styler Cannot read property className of null

Hello, I've run into some trouble with the Grid Cell Styler app.  I've gotten this working in other parts of my application, but now, whereever I try and use it, I'm getting the following error: Cannot read property 'className' of null TypeError: Cannot read property 'className' of null     at Object.remove (http://localhost:8080/mxclientsystem/mxui/mxui.js?636820652142062117:5:101138)     at O.(anonymous function).S._handleResults (http://localhost:8080/widgets/CellStyler/widget/CellStyler.js?636820652142062117:308:68)     at _loop (http://localhost:8080/widgets/CellStyler/widget/CellStyler.js?636820652142062117:236:31)     at O.(anonymous function).S._evalRules (http://localhost:8080/widgets/CellStyler/widget/CellStyler.js?636820652142062117:263:17)     at O.(anonymous function).S.a [as refreshGrid] (http://localhost:8080/mxclientsystem/mxui/mxui.js?636820652142062117:5:54082)     at O.(anonymous function).S.<anonymous> (http://localhost:8080/mxclientsystem/mxui/mxui.js?636820652142062117:51:104559)     at o (http://localhost:8080/mxclientsystem/mxui/mxui.js?636820652142062117:20:12970)     at s (http://localhost:8080/mxclientsystem/mxui/mxui.js?636820652142062117:20:12735)     at r (http://localhost:8080/mxclientsystem/mxui/mxui.js?636820652142062117:51:13942)     at http://localhost:8080/mxclientsystem/mxui/mxui.js?636820652142062117:51:14548 The one thing I have noticed is that where I have it working, the Data Grid (with data source set to XPath over an association) to the Data View the grid is nested in.  Also, the Data View listens to a Data Grid).  I think this might be an order of operation type of issue.  I've tried placing the grid cell styler before/after the Data grid and inside/outside the container.  Any suggestions much appreaciated. 
1 answers

Are there specific actions you invoke before getting this error? And what version of Mendix are you using?

I recall encountering similar issues when working in Mx 7.20 below for which I've had contact with Mx support about. The issue only appeared in specific cases.

(See also release notes of Mx 7.20:

"There is an issue when a microflow called from a pop-up window first rolls back the object that is the context of the page and that has not been committed yet and then closes the page. This can result in a JavaScript error and the page becoming unresponsive. (Ticket 70111)"