Thread:Extension talk:VisualEditor/Can't edit source tags

I'm using the buildly nights for MediaWiki, VisualEditor and have GeSHi extension installed. The visual editor is working pretty well, but I am not able to edit source blocks. A message like "sorry, this can only be edited in source code mode" appears when the mouse is over the source block.

I have one more question. How can I insert a source block?