SP Online embed web part error

[yeret]

I trying to use the embed web part in a SharePoint site, I already check this:

1. Add the domain in the HTML field security on the collection site configuration.
2. Obtain the iframe code from the source site.

But the error still apearing when I try to insert the iframe code, as shown in the following image.

Any help will be appreciated.

Thanks in advance.

[#2]

@yeret, I have had a similar problem. It seems to be a bug. Have you tried just putting the URL without the iframe? I found this helped me but it made it so I couldn't show the whole page without scrolling. 

This is something Microsoft needs to fix.

[#3]

@yeret Hello,

Have you added "miro.com" as a trusted site? If not, the embed can not load content from untrusted location.

Yours sincerely,
Aref Halmstrand