Invalid Editor Problem with Editable Reblogs 2.1.x

We have gotten lots of reports that, even if you are using Rich Text as your default post editor, it still says Invalid Editor type.

The message looks like this

Worry not, as we are already working on a fix for this error, as well as the HTML reblog problems that cause it to happen in the first place.

Until the update is out we strongly advise that you disable Editable Reblogs