My Forms editor displays incorrectly in IE. When I try to configure controls, the view of the form is limited - see attachment. So I tried to use Chrome. Received this error, however, Chrome is supposed to be supported:
Error - You have opened Nintex Forms Designer in an unsupported browser. Please close Nintex Forms Designer and reopen using one of our supported browsers as specified in the Nintex Forms installation guide, available for download from connect.nintex.com.