Read on if you are interested in a perplexing challenge we're facing.
The verbose version:
We run an old LMS platform called TopClass (perhaps more accurately we run
an old version of that software) in order to offer some online courses (not
to MSU students, this is with an outside group). In the last 3-4 weeks,
much of our user base has been reporting a confusing form submission problem
when taking assessments. In certain circumstances (usually but not always
the same assessments) submitting the form to the server will produce a blank
page sent back. At other times, the user will be presented with a "cannot
find server or DNS error" message. Looking at server logs and TopClass
internal reporting structures reveals that valid POST requests were made and
even that the users' submissions were captured/stored. I have not as yet
been able to replicate this behavior on our own machines, but I think that
that may be because of the XP Pro OS I am working with. All affected users
thus far have been using Windows 2000 Pro. More specifically they are state
government employees which means they don't have a lot of control over their
setups. I admit that I am stumped at this point: no updates to TopClass,
the server machine, or the users' systems were applied around the time this
problem started happening. One of my few guesses is that it is a network
issue, perhaps related to some network fritzes that MSU suffered a few weeks
back. Does anyone have any guesses as to what is happening and what I might
do to address this issue? It's getting to be a showstopper.
Now, the bulleted version:
Our setup:
-Windows 2000 Server/IIS, all MS updates and patches applied (some after
this started, but again none right around that time)
-TopClass v3.12, released either in 2000 or 1999. Source code not
available.
Problem behavior:
-HTML form submission of TopClass assessments returns blank page
-HTML form submission of TopClass assessments returns "cannot find server or
DNS error" page
-repeated page refreshes will sometimes yield the proper results, but often
not
-Server appears to be correctly accepting user POST request and processing
form data, even saving question responses properly
-No reliable reports of this problem prior to one month ago
-Problem does not occur on 100% of machines, does not occur 100% of the time
to affected users, and does not even affect every assessment. No other POST
errors have been detected, for example no complaints have been registered
about the authentication process.
-Repeated refreshes (repeat POSTs) sometimes yields correct output on users'
browsers, but not often enough to be generally helpful
-Old assessments and new assessments are both affected; for some assessments
in which problems were reported, the HTML presented to the user has not
changed in 4 years
Affected users common features:
-Windows 2000 Professional
-IE v6.0
-JavaScript enabled
-switching OS or browser not an option
Guesses and avenues of investigation:
-Network communication/routing error between server and client, causing
either corrupted or blank responses. Several locations in network chain are
plausible subjects of investigation, though lack of consistency in problem
details pushes me away from the idea of "it's the firewall" or anything so
straightforward.
-Blank page behavior view source code reveals page HTML created locally by
IE, suggesting server acknowledgement without proper content
-"cannot find server or DNS error" message suggests redirection?
If anyone is interested in trying to replicate this behavior backchannel me
and I can set up a demonstration. It's an LMS which means authentication,
so I can't just give everyone here a URL to look at. That also complicates
my own attempts to get information.
One final thought: is there some kind of software that we might run on the
users' computers that runs alongside IE and logs ALL the back and forth
between browser and server? Optimally it would be something that doesn't
require installation, as that would make the State folks antsy. I suppose I
could try asking them to use Telnet and walking them through some complex
instructions but that sounds very cumbersome.
Sorry for the long message, but we're starting to drive ourselves a little
crazy here trying to figure this out.
-Orion
|Orion A Smith, REACH Technology Coordinator|
|457 Erickson Hall, MSU (517)432-4022|
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