All in one video pack - 404 page error with WP User Frontend

I have installed “All in one video pack” on Wordpress to make a user community board which website users can upload video files on the website.
So I have installed “WP user frontend” plugin to let users post a message on the website.
To post a message via “WP user frontend”, I clieked the Icon - Add Kaltura Media, and new page poped up "404-page not found instead showing the page - video can be uploaded.
Here are the links.
404 error page
but if I add “wp-admin”, it will works.
For the testing, I have loged on the web as a admin account (test/test)
I need a help for this issue, anybody knows about it?