Good luck. I sign in and I can go to the design page and click comment but nothing happens for me. Same thing on YouEmbroidery. Tried particpating on the sites from the very beginning and I'm still not able to. I know others were making comments at the time about their trouble. Don't know if they ever had any luck. I know I haven't. Would love to be able to though. I'm glad Cute works for me!!
You need to be signed in. Then go to a design. Add comment boxes are on each design page.
Going to community takes you to Youembroidery and off of the Cross Stitch site so that's not the way to do it.