question about "Content Encoding Error"
albert
error I do not understand and wonder if it is correctable. It occurs
with Firefox, but not with IE8 [Firefox v3.6.13is my preferred browser,
and I rarely use IE].
This is the error I get- and it only happens with /some/ of the links
within each of the sites for which I provide links below. Additionally,
sometimes the error will appear one day - and if I go back to the site a
day or two later, the same link will no longer be problematic:
"Content Encoding Error"
"The page you are trying to view cannot be shown because it uses an
invalid or unsupported form of compression.
* Please contact the website owners to inform them of this problem.
My workaround is to open those links in IE8, which does not complain
about any compression problems with these pages.
While some pages at these sites cannot be opened by Firefox, the
overwhelming majority of those site's pages work very well in Firefox.
I am curious as to what the problem might be. I am not an HTML code
expert, so tho' I can and do view the problematic source pages, I
haven't yet discerned what key differences exist between the successful
and unsuccessful pages.
Here are examples of the problem:
This works just fine:
http://www.tweakhound.com/blog/?page_id=1185
this didn't work last week, except in IE8 - and today it works fine in FF:
http://www.tweakhound.com/linux/suse/101/installing_1.htm
this doesn't work, except in IE8:
http://www.tweakhound.com/mdk9/mandrake9.htm
This link, at the NY Times, either gives the above error, or, sometimes,
appears to partially load with a result that suggests that its CSS files
and graphics files are not loading. It works well in IE8.
Thanks for any insight and suggestions you can offer.
albert
Christoph Schmees
all those pages contain various errors. And IE definitely is more
tolerant to errors, as M$ own web design mock-up "Frontpage"
produces such terrible garbage ...
Christoph
--
email:
nurfuerspam -> gmx
de -> net
Ralph Fox
albert wrote:
> "Content Encoding Error"
>
> "The page you are trying to view cannot be shown because it uses an
> invalid or unsupported form of compression.
>
> * Please contact the website owners to inform them of this problem.
>
> My workaround is to open those links in IE8, which does not complain
> about any compression problems with these pages.
>
> While some pages at these sites cannot be opened by Firefox, the
> overwhelming majority of those site's pages work very well in Firefox.
> I am curious as to what the problem might be. I am not an HTML code
> expert, so tho' I can and do view the problematic source pages, I
> haven't yet discerned what key differences exist between the successful
> and unsuccessful pages.
I do not believe this has anything to do with the HTML code itself.
When a web browser requests a web page, it can also give the server
a list of compression methods which the browser will accept.
The idea is that if the server also supports one of these compression
methods, then the page will be compressed and transmitted faster than
if it was uncompressed.
A. What I think may be happening is that the data from the web server
is sometimes corrupted while in transmission to you. Most times
your computer will detect the corruption and request a retransmission.
The only effect you will see is that the download takes slightly longer.
However, sometimes the corrupt data gets through to Firefox. Firefox
notices a problem when it tries to decompress the data and the
corruption stops the decompression.
B. The other thing that might possibly be happening is that the web
server tries to use a form of compression which was not in Firefox's
list ("gzip,deflate").
I don't see the problem here, so I suspect it is 'A' and not 'B'.
IE (AFAIK) does not support all of the compression methods which Firefox
supports. It is likely that the web server is providing the data to IE
in uncompressed form. IE will not be doing any decompressing, so IE cannot
encounter problems in the decompressor even if a byte or two is corrupted.
Here is a test to try.
1. In Firefox, go to "about:config"
2. Look for the preference "network.http.accept-encoding".
3. Change its value to blank.
Q. Does this affect the problem?
4. To restore the preference "network.http.accept-encoding,
right-click on that line and choose "reset".
> Here are examples of the problem:
>
> This works just fine:
> http://www.tweakhound.com/blog/?page_id=1185
> this didn't work last week, except in IE8 - and today it works fine in FF:
> http://www.tweakhound.com/linux/suse/101/installing_1.htm
> this doesn't work, except in IE8:
> http://www.tweakhound.com/mdk9/mandrake9.htm
No problem here downloading the last of those three pages in Firefox.
I suspect that data corruption is occurring in transit between the server
and you, but not between the server and me.
Below is how Firefox requests the last page, and how the server responds.
• The line "Accept-Encoding: gzip,deflate" is where Firefox tells the
server which compression methods Firefox can accept.
• The line "Content-Encoding: gzip" is where the server tells Firefox
how the data (which follows) has been compressed.
|>Firefox>| GET /mdk9/mandrake9.htm HTTP/1.1
|>Firefox>| Host: www.tweakhound.com
|>Firefox>| User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13
|>Firefox>| Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
|>Firefox>| Accept-Language: en-us,en;q=0.5
|>Firefox>| Accept-Encoding: gzip,deflate
|>Firefox>| Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
|>Firefox>| Keep-Alive: 115
|>Firefox>| Connection: keep-alive
|>Firefox>|
|<<Server<| HTTP/1.1 200 OK
|<<Server<| Content-Type: text/html
|<<Server<| Content-Encoding: gzip
|<<Server<| Last-Modified: Sat, 12 Feb 2011 16:36:42 GMT
|<<Server<| Accept-Ranges: bytes
|<<Server<| Etag: "aaffa67d3cacb1:0"
|<<Server<| Vary: Accept-Encoding
|<<Server<| Server: Microsoft-IIS/7.5
|<<Server<| X-Powered-By: ASP.NET
|<<Server<| Date: Sat, 19 Feb 2011 03:30:20 GMT
|<<Server<| Content-Length: 8976
--
Kind regards
Ralph
clarjon1
> There is an error I encounter occasionally when browsing some sites - an
> error I do not understand and wonder if it is correctable. It occurs with
> Firefox, but not with IE8 [Firefox v3.6.13is my preferred browser, and I
> rarely use IE].
>
> This is the error I get- and it only happens with /some/ of the links
> within each of the sites for which I provide links below. Additionally,
> sometimes the error will appear one day - and if I go back to the site a day
> or two later, the same link will no longer be problematic:
>
> "Content Encoding Error"
>
> "The page you are trying to view cannot be shown because it uses an invalid
> or unsupported form of compression.
>
> * Please contact the website owners to inform them of this problem.
>
>
>
The work around that I've found to work well is to hit Ctrl-F5 -- reload
without any cache. This will re-send the requested compression type to the
server, and give you the page properly.
So far, it hasn't failed me yet!
David McRitchie
"clarjon1" <clar...@gmail.com> wrote in message news:mailman.28.1298126678...@lists.mozilla.org...
"some sites" is not very descriptive.
I doubt that I'd be able to answer the question properly, but you have not
supplied the url, which would make it possible for someone to know if
they are even close to answering your question properly. Must be on a
public site without a login for so that anyone can see it.
albert
Thanks for the tip - and I will certainly give it a try the next time I
encounter the error I described [since I wrote the original post, it
hasn't happened even once - which is how things go, of course - but I am
sure it will occur again]
albert
albert
> On Fri, 18 Feb 2011 15:48:20 -0500, in message<v_udnbEYc5K_RsPQ...@mozilla.org>
> albert wrote:
>
>> "Content Encoding Error"
>>
>> "The page you are trying to view cannot be shown because it uses an
>> invalid or unsupported form of compression.
>>
>> * Please contact the website owners to inform them of this problem.
>>
>
> No problem here downloading the last of those three pages in Firefox.
> I suspect that data corruption is occurring in transit between the server
> and you, but not between the server and me.
>
> Below is how Firefox requests the last page, and how the server responds.
> • The line "Accept-Encoding: gzip,deflate" is where Firefox tells the
> server which compression methods Firefox can accept.
> • The line "Content-Encoding: gzip" is where the server tells Firefox
> how the data (which follows) has been compressed.
>
>
> |>Firefox>| GET /mdk9/mandrake9.htm HTTP/1.1
> |>Firefox>| Host: www.tweakhound.com
> |>Firefox>| User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13
> |>Firefox>| Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
> |>Firefox>| Accept-Language: en-us,en;q=0.5
> |>Firefox>| Accept-Encoding: gzip,deflate
...........snip..........
Ralph,
What a great explanation - clear and detailed. You certainly help me
to learn, and you have amplified my understanding of what is going on
when I see this kind of error. It never occurred to me to search in the
direction you led me to.
BTW - a couple of questions about your analysis - for my further
understanding. [ONLY If you have the time and inclination - and you can
simply refer me to some online reading if you prefer].
1 -- The data you furnished about the communication between Firefox and
the server - did it come from the Live Headers add-on or some other
method? [I have the Live Headers add-on, but never much thought about
its utility for me until your response.]
2 -- where/how would one find out what compression methods a server is
set up to use? I assume there is some sort of inquiry one can make of
the server for which it will specify what it can furnish?
Thanks for all,
albert
Ralph Fox
albert wrote:
> 1 -- The data you furnished about the communication between Firefox and
> the server - did it come from the Live Headers add-on or some other
> method? [I have the Live Headers add-on, but never much thought about
> its utility for me until your response.]
It came from the Live HTTP Headers add-on.
> 2 -- where/how would one find out what compression methods a server is
> set up to use? I assume there is some sort of inquiry one can make of
> the server for which it will specify what it can furnish?
The usual process is that the browser sends the methods which it supports
and the server picks one of them.
Legal values are
gzip
compress
deflate
identity [no compression; always supported]
exi
pack200-gzip
To find what values the server supports, you could try sending each of
the above values by itself to the server, one by one in an "Accept-Encoding"
request header. Then see whether the server responds with the same value
in the "Content-Encoding" response header.
--
Kind regards
Ralph
albert
Again, thank you Ralph for your info and instruction.
albert