Embed Video - tinymce

I should elgg 1.8.3. Why can not I go Embed video from Youtube.
I set the editor tinymce, now I have a button and it adds a media video

image

Then click the button  insert and as shown in Figure yellow square - as it should be - then tinymce working properly.

image

- but after I clicked the save button

image

- everything disappears.

What is the cause. If the problem is not in the editor tinymce, but elgg please tell how to solve this issue.

Feedback and Planning

Feedback and Planning

Discussions about the past, present, and future of Elgg and this community site.