I'm the sole developer building a LAMP web application for a small infancy-stage startup and have been crying myself to sleep over a bug that only occurs when using the web app in Internet Explorer 10-11 and Edge (Chrome, FF, and Opera work like a charm). Worse yet, it happens randomly and about 50% of the time after a user has authenticated and logged into the web app. Here's a screenshot: 
Here's what shows up in the DOM Explorer when inspecting:
15447HTTP/1.1 200 OK
Date: Wed, 17 Aug 2016 09:27:27 GMT
Server: Apache/2.4.12 (Ubuntu)
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 4972
Keep-Alive: timeout=15, max=97
Connection: Keep-Alive
Content-Type: text/html; charset=UTF-8
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<more garbled text>
As one can see from the response headers, the server returned a status of 200, and there are no errors or warnings in the console. Under the 'Network' tab, everything appears to have returned with either 200 or 302, with the exception of a couple 404s when retrieving profile pictures from the LinkedIn REST API (the pics still show up though in the other 50% of the time that the page actually displays properly...). On the server side, there is nothing in the Apache error log, and syslog is clean. The actual content appears to be compressed, which shouldn't be a problem given that the server is specifying the content encoding as gzip. Either that, or I'm looking at encrypted content.
I'm running Apache 2.4.12 on Ubuntu 15.10. Content is (of course) served over HTTPS, and the cert doesn't expire for another year. The application is written in PHP, and this happens on both the staging and production servers. I've scoured SO, Serverfault, and Google for a similar problem but haven't been successful. If anyone has encountered this error before or has any possible idea as to what's going on, any help would be greatly appreciated.
