i cannot replicate this - what are you typing in the field
please post a screenshot so we can see what you mean by "Formatting in editor is crash.~"

0. I create my component for Joomla, he's good working.
1. One of any view's component in admin panel have editor field. I wan't add video in my editor.
2. I go TinyMCE settings and add 'iframe' in field "Valid elements".
3. After this actions i back to editor in view, editing this (add bold-style text or add image). It's correctly show in editor.
4. But after click on save button, text in editor show as simple text, without formatting, has no images and strong elements. Just text.

ah i see your problem now. if you enter anything in the "valid elements" field then they are the only valid elements. in your case you want to add iframe to the current valid elements so you should enter it in the Extended Valid Elements field which ADDS anything entered there to the standard list of valid elements

It's translation problem (I use russian language) or global problem?

i have no idea what it says in russian but it is correct in english

In russian language field's label is bad.
First field is good.
2'th and 3'th field's label is not corrrectly. It's not meaning.
2'th field good label - is "Разрешено использовать только следующие теги"
3'th field - "Кроме запрещённых разрешить следующие теги"

@infograf768 can you notify the russian translator please

@mbabker we need an easy process for this

Closing as not a bug in the joomla core. Hopefully the translators wil make the correction