The "Edit in Adobe Audition" is greyed out in After Effects CC. I imported an mp3 file into my composition, click on it and the link remains greyed out. The link works fine from Premiere Pro CC to Audtion.
Figured it out. For whatever reason the .sesx file extension wasn't associated with Adobe Audition on my Windows 7 machine. I changed this by double clicking on an .sesx file and adding the association.