Client Cannot Upload Files

[PedroDePacos]

Hello,
I developed a web application (in ASP.NET) that allows my client to administer her own e-commerce website. One of the functions that this application allows her to do is update her own products.

She can add, edit, and delete products on her website and the application also lets her upload product pictures from her local computer to the web server. This is where the problems lies. When she tries to upload any pictures to the server, the application hangs and she has not been able to upload any pictures.

I've tested this on 7 different computers at 5 different IP Addresses and they have all allowed me to upload pictures flawlessly. I've written error handling code for this routine but it is not called, so I can be almost completely sure that it is not a problem with my code. I believe that it is a problem with her computer.

I was hoping that someone could shed some light on this situation and maybe suggest some possibilities as to why she cannot upload files. I also think that she is not able to send file attachments in emails (at least she wasn't able to send her pictures to me through email), so maybe this is related.

I know that she recently had some problems with her computer, but she told me she just had a new hard drive installed. I've done some research and found that some trojans will affect the ability to upload any files to the Internet, but with a brand new hard-drive I'm not sure she's had time to pick one up. She's using windows XP and I don't believe she has a third party firewall installed. Could it be a simple setting that needs to be adjusted? Please, I'd appreciate any help in this matter.

[Lord_Rat]

Sounds like a problem with Internet Explorer / Windows Explorer (same program).

Try repairing IE / Upgrading IE.

Even if she is using a non-IE browser, this can still be the problem.

Without further details, I cannot be more specific.

[PedroDePacos]

What kind of details do you need?

[Lord_Rat]

What browser and OS.

What is the file format and file size of the file being uploaded

What internet connection speed does the client actually connect at

And finally,

What actually happens when the file is attempted to be uploaded? You said 'the application hangs'. Which application, and define 'hangs'.

[PedroDePacos]

1) Internet Explorer/Windows XP

2) Image files (jpg, gif, bmp) - sizes range up to 4 mb

3) Cable Internet

4) The application that I wrote that the client uses to administer her website hangs. Since I included error handling code into this image upload function, it should be called if there is an error, but it is not called. Nothing happens for a few minutes and then it shows the "This page cannot be displayed..." message.

[Lord_Rat]

Sounds like a timeout.

Check the upload speed, I'd be willing to bet she cannot upload those files in under 2 minutes (the timeout most browsers use).

[PedroDePacos]

It is a timeout, but why can I upload these files? We have the same ISP - should be approximately the same speed. Also, I sent her smaller files to upload and this also didn't work.

We also think that this problem is related to her not being able to send any files as attachments. If you read my first post, then I allude to this problem there as well.

Just to understand what you're saying about timeouts... if any process takes longer than 2 minutes then it will timeout?

[PedroDePacos]

I found the following information about IE and timeouts (http://www.daniweb.com/techtalkforums/showthread.php?t=1165)...

SYMPTOMS
When you connect to a Web site that runs for a period of time before it returns information to Internet Explorer, you may receive one of the following error messages:

Microsoft Internet Explorer error 10060 connection timed out.
-or-

Internet Explorer cannot open the Internet site <Web address>. The operation timed out.
-or-

The page cannot be displayed. Cannot find server or DNS Error.

CAUSE
By design, Internet Explorer imposes a time-out limit for the server to return data. The time-out limit is five minutes for versions 4.0 and 4.01 and is 60 minutes for versions 5.x and 6. As a result, Internet Explorer does not wait endlessly for the server to come back with data when the server has a problem.

RESOLUTION
In general, if a page does not return within a few minutes, many users perceive that a problem has occurred and stop the process. Therefore, design your server processes to return data within 5 minutes so that users do not have to wait for an extensive period of time.

You can usually break down long processes into smaller pieces, or the server can return status data to update users (and Internet Explorer) on the process status. In addition, you can create a long server process with a messages-based or asynchronous approach so that it returns immediately to the client after the job is submitted and notifies users when the long process is done.

_________________________________________________

I know that she is using IE 5 or 6, and I don't think that she would have changed the default. So according to the above information, the default timeout is 60 minutes. This problem occurs even if she were to use a 5 KB image file (and uploading this is instantaneous on my computer, so I figure it shouldn't take even close to 2 minutes).

[Lord_Rat]

Definitely suspicious.

Start her computer in "Safe mode with Networking" and try it there.

Is she going through a router at all?

[PedroDePacos]

She only has one computer at her office and she doesn't use a router.

[Lord_Rat]

Safe mode with networking doesn't assume she has a network, it's so that she can still go Online with her cable modem. The cable modem and her computer are a network.

[PedroDePacos]

I realize that but I just wanted to answer your question that you asked about her having a router.

I am trying to fix this problem remotely and I will try this as soon as I can get to the client's office.