Why does IE show junk for my dasBlog blog?

Question

If I look at my blog in Chrome or Firefox, it looks as I expect. However, if I try to look at it in IE (11.0.9600.17801) it asks me if I want to download W69NUE8S (or some other random file name), which looks like some binary file.

http://dotnetwhatnot.pixata.co.uk/

I tried deleting all my temporary files, but it didn't help.

Anyone any ideas?

Answer 1

The issue here appears to be the double-gzipping of the content. This is evident by the headers:

HTTP/1.1 200 OK
Cache-Control: public
Content-Type: text/html; charset=utf-8
Content-Encoding: gzip,gzip
...

Note the doubling-up on the Content-Encoding header. According to an older Firefox bug, this issue affected not only previous versions of Firefox, but also Internet Explorer, versions 8 and up. It appears as though Mobile Safari may also affected by this to some degree.

I was able to decode the content twice via a custom FiddlerScript, and confirm that this remedies the problem in Internet Explorer, and Microsoft Edge.

I'm going to open up a ticket on this for the Networking team to consider. In the meantime, I would encourage you to dial it back a bit, and only encode your out-going content once. This will ensure that users on older Firefox versions, and Internet Explorer will be able to see your content.

If you cannot modify the compression rules, your only other option is to disable it altogether for the time being.

I have replicated this issue here: http://sampsonvideos.com/experiments/gzipgzip.php