Posted on wrong forum, should have been 2.0 bugs
The new render method of BasicForm looks like this:
f.applyTo = f.id;
Since the container is not passed in to render, Component.render tries to find it if this.el is defined, but this.el only gets set through Component.applyToMarkup if applyTo was passed as an option to the constructor.
Instead of setting applyTo and calling render, should BasicForm.render call f.applyToMarkup(f.id)? or should Component.render check for this.applyTo?