Carefully following this issue SSRS IE8 JavaScript error Invalid Character ScriptResource.axd I did some debugging and narrowed the problem down to a problem with gzip, deflate.
We have different machines with IE8 installed on it. The problem is that some IE installations do not seem to add Accept-Encoding: gzip, deflate to the HTTP request header when requesting a JavaScript resource through ScriptResource.axd.
Here is the HTTP request from machine 1 (works fine):
GET http://10.xxx6/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.xxx6
And here is the same request executed with machine 2 (does not work as gzipped return data):
GET http://10.xxx6/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.xxx6 skCIGFrM350LrrgpIbuyQ3hv0Po2nyTqnjMC_h2orbb8AW34-wlapNOlKQn3w_65Hv8xicNrMgbLAWsuKLkB24a0JnVTM3AD64R_ELK1K6KpCKGgYkO_evQ1uY6IeQkuEpQDrHclftKpS0G8rnJM1 & t = 4d63fd9d HTTP / 1.1? GET http://10.xxx6/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.xxx6
The problem is that IE does not request gzipped data, but actually receives gzipped data from the server (then this fails because it does not consider it gzipped). If I manually decompress the data returned with zcat or something like that, I can view the returned JavaScript.
What can cause IE8 not to add this header to the request?