1431248 - Firefox update process corrupts my Windows User Profile

Status: RESOLVED INCOMPLETE

(Firefox :: Installer, defect, P3)

Description

[Leo]

Attachment: TempProfile-17Jan2018.png

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36

Steps to reproduce:

To be specific, it corrupts the NTUSER.DAT file that is in a user's home directory. The sequence of events is as follows:

1. My laptop is running fine, reboot after reboot.

2. One day, I start my laptop and, without doing anything else, open the Firefox browser, click Menu -> Help -> About Firefox.

3. Firefox automatically checks if an update is available. It turns out, there is an update, so it asks me to restart the browser to finish the update.

4. I restart the browser and check the FF version. It has updated from the previous version 50.0.2 to the new version 50.0.4. I then Exit the browser. (I do not have any Extensions/Plug-ins installed in FF).

5. After this I do absolutely nothing else on my laptop and shut it down. The next time I restart the laptop and try to log into the User Account that was used to update FF, it turns out, my Windows User Profile has been corrupted.

6. Windows logs me on with a temporary profile with the message:
"You have been logged on with a temporary profile. You cannot access your files and files created in this profile will be deleted when you log off...." (see the screenshot)

7. I log out and check other User Accounts on my laptop and they are all working fine.

Luckily, I happen to have a backup (uncorrupted) copy of the NTUSER.DAT file. So I replace the corrupted NTUSER.DAT file with the backup copy. This fixes the problem in a way and I am back into my user account as per the backed-up profile settings.

How come I had a backup copy of the NTUSER.DAT file? Well guess what! The above problem has been occurring repeatedly since around late October 2017. It absolutely wrecked my life (User Profile got corrupted several times). Only after wasting days and weeks trying to search for a solution, I learnt it was the NTUSER.DAT file that was getting corrupted and that I ought to keep a good copy of that file from now on.

Each time this happened, I can now recall I had updated the Firefox browser.

Another user seems to have reported a similar bug earlier, though under different circumstances:

https://bugzilla.mozilla.org/show_bug.cgi?id=1300738

In that post, someone mentioned the Avira Antivirus as a possible reason. But I don't have Avira!


Actual results:

The NTUSER.DAT file in the user's home directory (Windows 7 Home Premium 64-bit) gets corrupted after running Firefox update and the user cannot log into Windows.


Expected results:

The Windows User Profile should not have been corrupted.

Comment 1

[Gingerbread Man]

(In reply to Leo from comment #0)
> It has updated from the previous version 50.0.2 to the new version 50.0.4.

Firefox 50 is obsolete and no longer supported.

Comment 2

[Molly Howell (she/her) (no longer active)]

> In that post, someone mentioned the Avira Antivirus as a possible reason. But I don't have Avira!

Do you run a different antivirus or other security software? Since the patch for the bug you linked to (bug 1300738, it should be in 50.0 if I'm reading the bug right), we no longer directly touch any NTUSER.DAT, we only go through the normal Windows registry API's (like RegSetValueEx). And if doing that leaves you with a corrupt NTUSER.DAT, it's very very likely to be to be the case that some third-party software is interfering.

To reiterate this point, I would also encourage you to update to the latest version of Firefox, by manually updating using the installer if necessary; 50 is more than a year old and it is no longer supported.

Comment 3

[Leo]

Thanks, Gingerbread Man and Matt Howell, for the replies.

Oh I see, I didn't know 50.0 was obsolete. I just assumed if I let FF update itself, it would give me the very latest version every time. Will download the latest version and let you know how the installation goes.

I have the F-Secure antivirus running. I've had it on this laptop for years with no apparent problems.

Comment 4

[Leo]

OK a couple of updates:

1. Apologies for the wrong Firefox version number I reported in my original post. The original problem had occurred while upgrading from version 57.0.2 to 57.0.4 (not 50.0.2 to 50.0.4 as reported originally). Apparently the error occurred because my system had just recovered and, apprehensive about the consequences of starting Firefox again, at that time I was trying to recall from the top of my head. However, I have now double checked everything and the correct version numbers were as above.

2. Today I started Firefox again (after backing up my NTUSER.DAT file, of course). Once again I went to Menu -> Help -> About Firefox. This time again it showed that an update was available and asked me to restart to install that update. I restarted Firefox and upon checking the version number I noticed it had updated from 57.0.4 to 58.0. This was the only operation I performed after starting my Windows 7 laptop, and after doing this I logged out and restarted the laptop again. And surely enough, my Windows user profile had got corrupted again.

I managed to get back my Windows user profile by reinstating the backed up NTUSER.DAT file.

So this is a conclusive evidence that the inbuilt Firefox update process is somehow corrupting my NTUSER.DAT file - and it is happening with the latest stable version. Maybe Firefox updater itself does not touch NTUSER.DAT, but maybe it is triggering some process that does that?

Comment 5

[Molly Howell (she/her) (no longer active)]

Okay, thanks for the updates; glad to hear you were running 57 instead of being stuck on 50 this whole time!

I'm gonna be honest, I don't know what's happening here. I haven't seen this happen before, and I can't think of an explanation for it that doesn't involve some other software interfering in a weird way. And software that does things like that tends to be security software, which is why I suspect that first.

There are a couple of things you could do to get us some more information, if you're interested:
1) Make a new Windows user account and see if the problem continues to occur under that account. This isn't enough to actually diagnose the problem, but at least it would give us a place to start looking.
2) Use Process Monitor to capture any processes that are dealing directly with NTUSER.DAT. If you don't know how to use Process Monitor, you can follow the first few minutes of the tutorial at https://www.youtube.com/watch?v=IYE7XQsnhTM, just use "NTUSER.DAT" as the path filter instead of the directory that he uses. Let it capture while you run an update, and if it shows anything, save it to a file and attach it here (or you can e-mail it to me directly if you're worried about posting that publicly). That might tell us if any other process is messing with that file (it also might not, if that software has some way of hiding its activity).

Thanks again.

Comment 6

[Skippy Bosco]

This is 2 years old and no occurrence from the original reporter, or anyone else indicating this issue.

Should be marked as closed / won't fix.