Why am I seeing captive portal requests on my home network? I have suddenly started getting prompts on my 2014 Mavericks MBP (10.9.5) every five minutes that bring up a page with HTML like the following:

&lt;HTML&gt;&lt;HEAD&gt;&lt;TITLE&gt;Success&lt;/TITLE&gt;&lt;/HEAD&gt;&lt;BODY&gt;Success&lt;/BODY&gt;&lt;/HTML&gt;


At the bottom of this modal window is a url:

http://www.apple.com/library/test/success.html


I am on my home network which uses an Airport Extreme running 7.6.4.  I did not make any known configuration changes to either my computer or my network.  Why am I suddenly seeing this page, which other posts suggest is a captive portal test?

I saw another question that demonstrated how to disable the Captive Network Assistant, but as I do take my computer to hotels that use these portals, I'm reluctant to jump straight to that.  Instead, is there something on my Airport that is generating/blocking these all of a sudden and it shouldn't be?  I tried a factory reset of the Airport and I'm still seeing this issue.

How can I configure my network so I stop getting these annoying popups?
The page has now been corrected, which should mean that the popup no longer occurs.