Closed Bug 1304848 Opened 7 years ago Closed 7 years ago

Users report Firefox is no longer launchable after the 49 update with a mozglue.dll missing error instead


(Core :: General, defect)

49 Branch
Not set



Tracking Status
firefox49 + affected


(Reporter: philipp, Unassigned)



(Keywords: regression)

we got a handful of reports from users at sumo saying they are no longer able to start the browser after they performed an update to 49 and are seeing a windows error message: "The program can't start because mozglue.dll is missing from your computer. Try reinstalling the program to fix the problem."
but reinstalling apparently doesn't help. at the moment we don't have much more information by those user to go on. should we look out for something in particular?
Liz, are you aware of these reports?
Flags: needinfo?(lhenry)
Tracking for 49. Thanks philipp and Ben. 
Benjamin can you give advice on what we should be asking for on SUMO from affected users and maybe help find an owner to investigate this bug?
Flags: needinfo?(lhenry) → needinfo?(benjamin)
I just verified that the installer contains mozglue.dll.

This sounds like it might be antivirus software quarantining mozglue.dll. Finding out if the affected systems have antivirus software and if they do details of their antivirus software would be the next step.
rstrong is correct. It's not clear to me who actually owns this next step though. Liz is that you, or somebody from SUMO?
Flags: needinfo?(benjamin) → needinfo?(lhenry)
Rachel or philipp, maybe this is something you could follow up on and bring some info back into this bug.
Flags: needinfo?(lhenry) → needinfo?(rmcguigan)
One user has reported it is AVG Antivirus causing the issue.
The same person also got an error 
< Firefox cannot start correctly (0xc0000022) after version update
That error apparently  occurs if Firefox is reinstalled and AVG is renabled.
we got more people confirming that they are using avg - can we do some outreach to them, as user feedback suggests this is quite a common issue?:
Flags: needinfo?(lhenry)
We could note it as a known issue, and I will try contacting AVG. 
Florin, do we have test versions of AVG software to try to replicate this?
Flags: needinfo?(lhenry) → needinfo?(florin.mezei)
I've tested on 2 machines with Windows 10 x64 and on one machine with Windows 7 x64 using latest free AVG version (from - basic protection and full protection (free 30-day trial AVG PRO). I've covered the following scenarios: 

- install 48.0.2 win32 build (under C:\Program Files(x86)\Mozilla Firefox) -> updated to 49.0.1 - Firefox correctly launch (mozglue.dll is NOT missing)
- install 49.0 build 4, win32 build - full installer (under C:\Program Files(x86)\Mozilla Firefox) - Firefox correctly launch (mozglue.dll is NOT missing)
- install 49.0 build 4, win64 build - full installer (under C:\Program Files(x86)\Mozilla Firefox) - Firefox correctly launch (mozglue.dll is NOT missing) 
- install 49.0.1 build 3, win32 build - full installer - Firefox correctly launch (mozglue.dll is NOT missing)   
- install 49.0.1 build 3, win32 build - Stub installer - Firefox correctly launch (mozglue.dll is NOT missing)  

I wasn't able to reproduce the issue. I'll also continue testing with several older AVG free versions and follow-up with the results.
Flags: needinfo?(florin.mezei)
This may be a (very) long shot, but could bug 1285356 be related to this, and the reason why this shows in 49 but not in 48 (which seems to be what users are reporting)?
one affected user reported back and said they were using avg version 2014.0.4158
Aaron, what do you think about comment 11? Maybe sandboxing related?
Flags: needinfo?(aklotz)
Not related. That bug was about changes that caused the blocklist to be ineffectual but was not really due to the sandbox itself.
Flags: needinfo?(aklotz)
Unfortunately I have not found avg version 2014.0.4158 or other old versions available.
I did contact Greg from AVG who put me in touch with one of the security engineers. I'll try emailing them again.
From feedback from users on SUMO, it sounds like updating AVG may solve the issue.
Are we still seeing any reports along these lines?
Flags: needinfo?(madperson)
no, the last reports on sumo about this problem are 2-3 months old. we have one thread about this which has more than 10k views, which is exceptionally much though for any issue on the site:

there's probably not much else that we can do about the issue...
Flags: needinfo?(rmcguigan)
Flags: needinfo?(madperson)
Closed: 7 years ago
Resolution: --- → INCOMPLETE
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