I have inserted a web part on a Sharepoint (2010) page that displays contents from another web page. This displays fine in Chrome, but neither works in Internet Explorer nor Firefox. The web page by itself (navigated in a different tab/window) works fine, but not when it is displayed as a web part.
Internet Explorer - error message:
Content was blocked because it was not signed by a valid security certificate. For more information, see “About Certificate Errors” in Internet Explorer Help.
Firefox - error message:
Your connection is not secure. The owner of has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website.
Is this a Sharepoint problem (since the web pages don't work in the Sharepoint web part) or other problem? And is there a solution for this?