This question has been asked before and no definite answer has been given.
I'm working with Sitecore 6.4 and Web forms for marketers 2.2.0 rev 110303. I have created a form with 'Send email' -action. When I open the action in editor, I cannot see any fields in the 'Insert field' -drop-down list. I have created a few test fields on the form.
In this post it was suggested, that the problem was in rev_110324 of the Web forms for marketers: Sitecore - Web Forms for Marketers - Send Mail Editor: No option was shown on the Insert Field drop down list
I have tried adding the site to IE's trusted sites list, but that did not help. I would like to know if this is some kind of a configuration issue or a bug in rev 110303.
Thank you for your replies in advance!
Just posted a solution where setting the Display Name of HTML Editor Button in Core fired up the dropdown list (finally) that worked for us.
Sitecore - Web Forms for Marketers - Send Mail Editor: No option was shown on the Insert Field drop down list
Hope it works for you too.
~Cheers