The embedded page is blank or refuses to display

This site only allows Offision’s own address and nothing else, so every frame on your portal is refused however the list is filled in — the Allowed websites rows are not even shown while it is selected.

On Security setting, set Can be embedded in to Listed websites for the app in the frame, add your portal’s address, and save. Note the two apps have their own choice: setting the user app leaves the visitor app as it was.

A browser compares scheme, host and port together, and refuses on any difference. These all look like the same site and are not:

• the list says https://portal.example.com, the page is served over http
• the list says https://example.com, the page is at https://portal.example.com
• the list says https://portal.example.com, the page runs on :8443
• the list says https://*.example.com, the page is at https://a.b.example.com — a wildcard covers one level only

Read the address out of the portal page’s own address bar and copy it into Allowed websites exactly, dropping everything from the first / onwards.

An address with a path on it, a bare *, or http:// on a public domain is refused when you save, and the screen refuses the whole save rather than storing the other rows. It is easy to leave the page believing the list was written.

Re-open Security setting and check the row is actually there. What the field accepts is listed in choose which websites may embed Offision.

The list is sent with the page, so a frame that was already open keeps the answer it was given. Reload the portal page — a hard reload, since the browser may have the old answer cached.