A non-secure URL in a secure page in a frame won't open unless opened in a new tab.
When I click on non-secure link in secure page in a frame it won't open the URL unless I open it in a new tab. If I change the non-secure link to a secure link in a secure page in a frame I can open the URL in the page. If I open the page with no frame I can open the non-secure link in the secure page. It seems to be the frame is stopping the non-secure link opening.
Alla svar (3)
This is about blocking mixed content on a secure web page. You can check the Web Console for security related messages. You will probably see something like: "The operation is insecure". Frames can open all kind of pages and in a secure page all frames need to be secure just like JavaScript files need to be loaded via a secure connection.
I will have to redesign my entire site or put information for users on how to open the links using open in new tab. This is not insignificant.
What messages do you see in the Web Console?