Following on closely from this question SSRS IE8 JavaScript Error Invalid Character ScriptResource.axd I have done some debugging and narrowed the issue down to a gzip, deflate problem.
We have various machines with IE8 installed on them. The problem is, some installations of IE don't seem to add the Accept-Encoding: gzip, deflate to the HTTP Request header when requesting a JavaScript resource via ScriptResource.axd.
Here is the HTTP request off machine 1 (works fine):
GET http://10.x.x.x6/Reports_2/ScriptResource.axd?d=dz2_T_-skCIGFrM350LrrgpIbuyQ3hv0Po2nyTqnjMC_h2orbb8AW34-wlapNOlKQn3w_65Hv8xicNrMgbLAWsuKLkB24a0JnVTM3AD64R_ELK1K6KpCKGgYkO_evQ1uY6IeQkuEpQDrHclftKpS0G8rnJM1&t=4d63fd9d HTTP/1.1
Accept: text/html, application/xhtml+xml, */*
Accept-Language: en-GB
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)
Accept-Encoding: gzip, deflate
Proxy-Connection: Keep-Alive
Authorization: Negotiate TlRMTVNTUAADAAAAGAAYAJIAAAAYABgAqgAAABgAGABYAAAAEAAQAHAAAAASABIAgAAAABAAEADCAAAAFYKI4gYBsR0AAAAP5M9BpXhDtQyLRxQO0MslBkQARQBOAEIASQBHAEgAUwBIAEkAUgBFAGEAbAB5ADgANgA3ADcANwBEAEMAQwAwADEAOQA4ADgAOAAW1o72sWx0hAAAAAAAAAAAAAAAAAAAAAD8+dJyp0KpjG5sP9WUlmrk4FptdhpYQAEETsImSmR+ZzMapF8Z91Wv
Host: 10.x.x.x6
And here is the same request made off machine 2 (doesn't work as its returning gzipped data):
GET http://10.x.x.x6/Reports_2/ScriptResource.axd?d=dz2_T_-skCIGFrM350LrrgpIbuyQ3hv0Po2nyTqnjMC_h2orbb8AW34-wlapNOlKQn3w_65Hv8xicNrMgbLAWsuKLkB24a0JnVTM3AD64R_ELK1K6KpCKGgYkO_evQ1uY6IeQkuEpQDrHclftKpS0G8rnJM1&t=4d63fd9d HTTP/1.1
Accept: image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/x-ms-application, application/x-ms-xbap, application/vnd.ms-xpsdocument, application/xaml+xml, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*
Accept-Language: en-gb
User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET4.0C; .NET4.0E; BRI/2)
Authorization: Negotiate TlRMTVNTUAADAAAAGAAYAIIAAAAYABgAmgAAABgAGABIAAAAEAAQAGAAAAASABIAcAAAAAAAAACyAAAABYKIogUBKAoAAAAPRABFAE4AQgBJAEcASABTAEgASQBSAEUAagBvAG4AOQA0ADYAMQA0AEQAQwBDADAAMQAzADUANgA2APyGLo3yOcCnAAAAAAAAAAAAAAAAAAAAABccpJT8TohKqbhq3PzWDPApr1NmEypAPg==
Connection: Keep-Alive
Pragma: no-cache
Host: 10.x.x.x6
The problem seems to be that IE is not-requesting gzipped data, but its actually getting gzipped data from the server (an then its failing because it doesn't think its gzipped). If i manually decompress the data returned using zcat or something, i can view the returned JavaScript fine.
What would cause IE8 not to add this header onto the request ??