After adding the code, didn't observe any other issues.
Thank you very much! Your 'possible fix' works for me.
In my situation it had nothing to do with setting the animation configuration to false, but with the following:
In my application I use one main view (Tabpanel). My main view has 4 items in it that extend Ext.Container. To each of these items I added listeners: activate and deactivate. On activate it 'lazy loads' the needed child elements. On deactivate it triggers: this.removeAll(true), which removes all child elements. I do this to keep the DOM as small as possible.
Now where it goes wrong:
When I activate one of the items in Tabpanel, then scroll down and activate another item from the Tabpanel (while the item is still scrolling) I get the following error:
Cannot read property 'style' of undefined in CssTransform.js.
I discovered this doesn't happen al the time. In my case it only happens when the scrolling animation is almost finished (when the scrollbar is bumping back from the top or bottom after it reached his end point).
After modifying CssTransform.js with the given fix it's now longer a problem.