Success! Looks like we've fixed this one. According to our records the fix was applied for
a recent build.
Docs issue - Ext.form.Pane#scrollable doesn't list null as acceptable value
After updating to ST 2.1.1 I was getting the following warning "[WARN][Ext.form.Panel#applyScrollable] This container is set to scrollable: false but has no specified height. You may need to set the container to scrollable: null or provide a height." It actually helped, but the issue is that docs for Ext.form.Pane#scrollable don't mention `null` as acceptable value at all or how is it different from `false`.
Thanks for the report! I have opened a bug in our bug tracker.