Hi, That functionality uses Java, Flash and the file manager. Since all of these plugins are updates, could it be an add on affecting the functionality? To test this:

• Does this happen in Safe Mode? Diagnose Firefox issues using Troubleshoot Mode
• Does Firefox have permissions to access other the other files' location?

Does this happen in other websites where uploading a file has the same dialogue?

Problem does not arise when uploading to DriveHQ and the problem does NOT go away running in Safe mode.

I'm inclined to try re-installing an older version of FF - but perhaps not, I can use IE to upload when I need to. Shame though!

What about the file permissions? Have you also tried resetting Firefox?

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information.
Note: This will cause you to lose any Extensions and some Preferences.

• Open websites will not be saved in Firefox versions lower than 25.

To Reset Firefox do the following:

For Firefox 29.0 and above:

1. Click the menu button , click help and select Troubleshooting Information.Now, a new tab containing your troubleshooting information should open.
2. At the top right corner of the page, you should see a button that says "Reset Firefox". Click on it.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

Thank you.

Reset did not help