436116 - Displays alert "Please enter a valid file" when I try to upload a file to Blackboard

Status: RESOLVED FIXED

(Tech Evangelism Graveyard :: English US, defect)

Description

[Boe]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9) Gecko/2008051206 Firefox/3.0
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9) Gecko/2008051206 Firefox/3.0

In Blackboard 8.0 Grade Center, while using Firefox 3 RC 1, when I try to upload an excel grade data spreadsheet, I get the alert "Please enter a valid file" when I click submit. 

This works fine on Firefox 2, so I know the files are valid.

Reproducible: Always

Steps to Reproduce:
1.Log into Blackboard 8.0.
2.Click Control Panel with a course site
3.Click Grade Center under Assessments
4.Click Manage, then click Upload
5.While on the Upload Grades page, click Browse and choose a .xls file.
6.Click Submit
Actual Results:  
Alert: "Please enter a valid file"

Expected Results:  
Uploaded the file and proceeded to the next screen.

Comment 1

[Jesse Ruderman]

"Please enter a valid file" is Blackboard's string, not Firefox's.  My guess is that they're using JavaScript to try to determine whether you have selected a file in the file upload control, and their script is getting confused by the change in bug 143220.  See also bug 405630.  It would be great if you could get the Blackboard people to fix this bug within the next few weeks, before Firefox 3 is released ;)

Comment 2

[Christopher Skelton]

Actually, the problem occurs regardless of the file type.  Don't know that it matters, considering what Jesse said, but just thought I would mention it.

Comment 3

[Christopher Skelton]

I guess I should clarify.  This happens on the student side, too, when trying to upload files attached to assignments.

Comment 4

[timeless]

does this demo service work? if so, please provide precise steps....

Comment 5

[Mark Hufe]

Attachment: Screen shots showing valid file selection and Firefox rejection

This is a major problem for students. BlackBoard is widely used and this bug prevents students from submitting homework. Students have to use a different browser (e.g. IE) in order to complete assignments. Instructors will have to advise students to use a different browser in their courses. It's really a show stopper for any course using Bb.

Comment 6

[Jesse Ruderman]

As I said in comment 1, I believe this is a Blackboard bug rather than a Firefox bug.  Please complain to them.

Comment 7

[Mark Hufe]

You may be right. Opera exhibits the same problem. But, the long and the short of it is, BlackBoard has a huge user base in universities. The users can't not use BlackBoard. It does work with IE and did work with Firefox 2. Something changed from Firefox 2 to Firefox 3 that caused the bug in Bb to manifest itself. The user base will have to go to IE out of necessity and will perceive Firefox 3.0 as the problem. I just want the problem fixed. I'll report the bug to Bb. And, for what it's worth, I'm an instructor and I wear a Firefox polo to school.

Comment 8

[Jesse Ruderman]

What changed from Firefox 2 to Firefox 3 was that we fixed a privacy/security hole, bug 143220.  Opera never had that hole (or had already fixed it), so it's not surprising that Blackboard is broken in Opera in the same way.

Comment 9

[Mark Hufe]

Not sure what all of this means, but there is an add-on that fixes the problem. "User Agent Switcher". Here's a link to the blog that gives the directions for it: http://www.shsu.edu/~ucs_www/webdev/blackboard/blog/2008/07/blackboard-and-firefox-3-assignment.html.

Since FireFox 3 fixed a privacy/security hole that may have something to do with why BlackBoard 8 has a file handling compatibility problem, I wonder if this add-on, which fixes the incompatibility, breaks the fix for the security privacy hole?

Comment 10

[Jesse Ruderman]

Probably not.  User Agent Switcher just changes how the browser identifies itself to web sites.  I bet Blackboard's JavaScript just does the check differently (and more correctly) when it thinks the operating system is Mac.

Can you look at the relevant BlackBoard JavaScript, attach it here, and confirm that's the case?

Comment 11

[Mark Hufe]

Attachment: Blackboard Javascript without User Agent Set to 'mac'. This is the failure scenario.

I haven't looked at the javascript, but the script captured when the user agent was not set to mac is the one in which the file handling fails. In this case, I tried to set up an assignment in Bb and to upload a support file. That failed. There were two alert type dialogues. After clicking through both of them, I did a view source and then a 'save source as'. Once the user agent is set to mac, the upload works fine.

Comment 12

[Jesse Ruderman]

Can you grab the file /javascript/validateForm.js from your instance of Blackboard and attach it here?  I bet that's where the relevant code lives.

Comment 13

[Mark Hufe]

Attachment: I think this is validateForm.js (it's been renamed from cache)

Not sure if this is the one. I did about:cache in the location bar. That gave me the name of the file and a pointer to a cache file. I looked in the cache file and saved it as validateForm.js. However, it seemed like "Please enter ..." alert should have been somewhere. It was neither in the source of the web page nor in the javascript file.

Comment 14

[Jesse Ruderman]

I don't see anything obviously wrong in inputFileCheck.  But that's also not where the "Please enter a valid file" string is coming from :/

Comment 15

[Mark Hufe]

Attachment: Here's the javascript with the "Please enter valid file message."

This is the BlackBoard Javascript code that reports a file handling error in Firefox 3.0.

Comment 16

[Jesse Ruderman]

Yeah, that script is wrong in pretty much the way I expected, and it makes sense that it breaks after the fix for bug 143220.  The weird thing is that the script contains a comment mentioning Firefox 3 but there's no code associated with that comment.

Comment 17

[Jesse Ruderman]

Thanks for finding the relevant script.  Can you contact the Blackboard folks and ask them to fix it?

If they want to check for Firefox (in order to continue checking for a full path in other browsers), they should look to see whether the user agent string contains "Gecko/".  They can do something similar for Opera too, I guess.  But I'd prefer if they dropped the check entirely, so they don't have to modify their script every time another browser fixes this security hole.

Comment 18

[David Humphrey (:humph)]

We're hitting this too, and it sucks.  However, I've spoken to our Blackboard admin, and says that there is a fix from Blackboard for this.  I'd recommend you get your institution to install it.

Comment 19

[David Humphrey (:humph)]

I tried to get a URL to the patch, but apparently your Blackboard admin needs to contact his/her TSM (Technical Support Manager) at Blackboard to get the patch.  Resolving.

Comment 20

[randdinc1]

I am finding the same thing happening again with the newer 3.5.2 version. However it does not happen with 3.0.13 version.