Firefox Suddenly Won't Download Files

[polo_step]

[I'm trying to diagnose this from a distance on someone else's computer, so bear with me...]

The user says that when he tries to download a file, the little download arrow in Firefox shows that the file is downloading and after it appears to be done, clicking on it reveals the downloaded file's name -- but when he clicks on the file, it vanishes. The file does not appear to be in the Download folder shown in the Firefox options. This function used to work properly.

Thanks for any tips on where to start with this.

OS = XP, Firefox version ~32

[malliz]

Security software would be my first guess after that you have to look at the location of his/her download folder and see if its set as read only

[polo_step]

Security software was removed. Highly unlikely Downloads was changed to read-only, but will check.

[Grumpus]

What type of file? Did you check the /tmp or /temp folders for the file? . . . maybe do a system search for it?
Reason: some files will migrate or disappear do to location.
Looking at (if Windows) /Tools/Options/General /Downloads -
. . . if Save Files to is checked what is in that text block?
. . . is Ask me where to save files checked? . . . have you tried closing and reopening Firefox before proceeding?

[therube]

when he clicks on the file, it vanishes

Not sure I'm following that?

[Grumpus]

when he clicks on the file, it vanishes

Not sure I'm following that?

Sometimes a file may register as a name in a directory but in reality it's only an image of the name and the rest of the file is void, incomplete.
Seen this with some PDF files, if the Adobe reader wasn't of the prescribed version/update, sometimes a notice and sometimes no notice as the name is not complete. Could be intrusion and the nefarious code has wandered off to it's end location. One of the reasons to do a system wide virus/rootkit sweep and search for new files.
Also, this sometimes occurred with other types of media files which seemed to load but did not and the timeout for the connection mimicked the end of download, file disappeared out of /tmp or /Downloads.
Ran into this two days ago when images from a site which were saved and were visible in the downloads disappeared when moved to another location in the system where permissions were tighter. Could not open them, simple jpegs and were lost. Came from the Google images I was searching. Just made sure they were gone and added a sweep.

[therube]

name in a directory but in reality it's only an image of the name

Nah, I wouldn't think that.

Now the file being a name in FF's Download Manager & no actual file having ended up on the drive, that I can (& have seen). [Likewise you'll see something along the lines of "cancelled" in FF's Download Manager, maybe with a size of 0.]

[Grumpus]

Wouldn't say it if it ain't so.
Having experienced it would think it's a downloaded file which has contents deleted somehow with the name still registering.
Similar to the images which disappeared the other day leaving the file names.