Managed VF Page with Cross Origin Problem to /_nc_external/system/security/session/SessionTimeServlet

Question

I have a managed VF page with header="true" and sidebar="false" that occasionally shows this in the JS console, and never seems to show the session timeout popup window that generally occurs.

XMLHttpRequest cannot load https://na12.salesforce.com/_nc_external/system/security/session/SessionTimeServlet?buster=1425614285835. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'https://mahnamespace.na12.visual.force.com' is therefore not allowed access.

Does anyone know of a workaround to get this method working using a relative url? I assume this fix would also get the session timeout popup window working again. I currently have none and am aware of no VF config around this feature.

Answer 1

There is a configuration of that feature in the setup, so first check this:

If you have this enabled, it should work and I don't think there is much you can do on your end. It definitively should work with Managed Packages, too.

You could check for the presence of interfering JavaScript. If you are the author of the Package you could add a blank VF Page with no JS included. Also deactivate all custom Sidebar Homepage Components. If you go to that blank page and stick there for the timeout threshold and the popup doesn't show up, it's time for a support ticket, I guess.