We have upgraded our AEM instance 188.8.131.52 to 184.108.40.206 after upgrade Touch UI dialog rich text box is not working.
When I open touch UI dialog I am not able to edit the rich text box field its showing below error.
Try using the latest Coral UI resource types. If still does not work, Log a daycare ticket and provide the steps to reproduce for further testing.
 Getting Started | CoralUI