I installed K2 (newest version) on my website, I also installed JCE 1.5.7.5 ( the newest). When I add item on backend, it displayed well. But when add a new Item in Frontend, it only showed this :

As you see, no editor is displayed. And another button button doesn't respond when I click on it. It stil showed this page, whatever I did.I also installed advlink plugin for JCE, enable all plugins, do group permission, disable/enable template CSS....but it didn't solve. I saw some people also get this problem too, and still not get a best answer.I think the popup editor is a cool idea, but not a very good way. Look forward to answering me soon.

Did you set jce as yor editor in admin users?

Of course, I set in Global Configuration, JCE Control Panel, in user panel . Everywhere relative with Editor, but the problem still there.

And it happens only with jce??? have you tried to set a different editor?

I tried to use TinyMCE, and it still happen. Maybe I will reinstall K2 .

Do you have this plugin (System - Mootools Upgrade) enabled in jour joomla??? Maybe it doesn't works because of this...

I have the same versions/ same problem. In addition, I am having issues Saving or Cancelling in the front end editor. Sure would like to use JCE in the front end.

same problem. Developers working on a solution?

In JCE admin panel you have some options to assign JCE to Groups and Users (frontend too) and Users.

Try to play with it.

Yes BBC is right: It has worked for me when I added the specifics frontend users, one by one, In JCE admin panel >> Groups >> FrontEnd >> Add Users (At page button)