I have a button that creates a new tab and loads some simple HTML and an iframe with a data URI passed into it. The new tab opens and I can see that this is all displayed in the DOM using the navigation tools (F12). However the Iframe does not display in Edge browser. I receive the error
HTTP404: NOT FOUND - The server has not found anything matching the requested URI (Uniform Resource Identifier).
This might be your issue: MSDN data Protocol.
For security reasons, data URIs are restricted to downloaded resources. Data URIs cannot be used for navigation, for scripting, or to populate frame or iframe elements.