Firefox Won't Launch Unless BitDefender is Disabled
Around midday, today (08 Dec 2020), a tab in Firefox crashed. Afterwards, any open Firefox window or tab would not respond.
I closed all sessions of Firefox, and confirmed all were closed in Task Manager. Then, any attempt to launch Firefox produced a spinning circle for a few moments, and then nothing. I did extensive searching and did all the suggestions I found. Installing/reinstalling did not change anything. I moved my profile to another location, and tried to launch Firefox (without success), and a new profile was not created. The Profile Manager would not launch. Firefox would not launch in Safe-Mode. I uninstalled Firefox and manually removed all folders and ran Ccleaner to clean up the registry. I then reinstalled without success.
I tried to roll back the system to a previous restore point of 03 Dec 2020, but that was unsuccessful; there was a suggestion from Microsoft that my antivirus was preventing the restore from being successful. I disabled BitDefender and tried to restore again, with the same failed result. I ran "sfc /scannow", which found some problems and fixed them. After Rebooting, I discovered that Firefox launched and worked as expected, but then realized that BitDefender was disabled. After enabling BitDefender, Firefox doesn't launch.
I added "c:\Program Files\mozilla firefox\firefox.exe" as an Exclusion in BitDefender, without success.
When trying to roll back the system, the feature to scan for affected programs showed I was using Version 69 of Firefox on 03 Dec 2020.
Did I receive a Firefox update today that caused Firefox to not play well with BitDefender? or is there something else suspected to cause BitDefender to prevent Firefox from launching?
I am running 64-bit Windows 10.
Chosen solution
Thank you for your suggestions. I have good news; I am back in business.
I uninstalled Firefox. Then I deleted the Mozilla folder in the Program Files folder and where the profiles are stored.
Then, I cleaned the cache and registry with Ccleaner. I repeated the registry cleaning until no more issues were found.
Then, I downloaded and installed Version 69...success. Then, I selected the Update option "Check for updates but let you choose to install them", to prevent updates from automatically being applied.
Then, I imported my bookmarks from a copy of the profile I had saved before deleting the folders...success.
Then, I let Firefox update itself to Version 72...success.
Then, I let Firefox update itself to Version 83...success.
Now, I will let BitDefender know the current status of my issue.
Read this answer in context 👍 0All Replies (9)
Disable BitDefender and contact their support.
I can't contact BitDefender, as I am using the Free version. Support is only available for users of paid versions.
When searching for how to get support from Firefox, I was directed to this forum. I didn't expect to be fobbed off and blame BitDefender; both applications must work together to ensure they are compatible.
I am going to try an earlier version of Firefox to confirm the issue is related to an update to Firefox.
Modified by t5montecarlo
It sounds to me that you need to create a new profile. I don't know how you do that on Windows but it should be easy to find out; perhaps search for "Firefox Profile Manager" or "create new Firefox profile".
Some security suites have an anti-exploit feature that hooks into other programs. Firefox 68+ uses a Launcher Process to try to prevent DLL injection, and sometimes this leads to a deadlock between the security software and Firefox.
Even with a free version of Bitdefender, you might be able to find help on turning off individual features to test whether those are causing the problem, or make exceptions for certain programs/folder. You also could check their forums to see whether others are mentioning new issues with Firefox.
terauck said
It sounds to me that you need to create a new profile. I don't know how you do that on Windows but it should be easy to find out; perhaps search for "Firefox Profile Manager" or "create new Firefox profile".
I had thought that at first, but with a new Firefox installation and the default profile, the behavior is the same; Firefox won't launch.
jscher2000 said
Some security suites have an anti-exploit feature that hooks into other programs. Firefox 68+ uses a Launcher Process to try to prevent DLL injection, and sometimes this leads to a deadlock between the security software and Firefox. Even with a free version of Bitdefender, you might be able to find help on turning off individual features to test whether those are causing the problem, or make exceptions for certain programs/folder. You also could check their forums to see whether others are mentioning new issues with Firefox.
These are good suggestions. However, there is only 1 feature in the free BitDefender that can be toggled, which is to enable or disable the Protection Shield. Their community forum has nothing of relevance.
I did find that I had contacted BitDefender in the past, so I have contacted them again...fingers crossed.
Chosen Solution
Thank you for your suggestions. I have good news; I am back in business.
I uninstalled Firefox. Then I deleted the Mozilla folder in the Program Files folder and where the profiles are stored.
Then, I cleaned the cache and registry with Ccleaner. I repeated the registry cleaning until no more issues were found.
Then, I downloaded and installed Version 69...success. Then, I selected the Update option "Check for updates but let you choose to install them", to prevent updates from automatically being applied.
Then, I imported my bookmarks from a copy of the profile I had saved before deleting the folders...success.
Then, I let Firefox update itself to Version 72...success.
Then, I let Firefox update itself to Version 83...success.
Now, I will let BitDefender know the current status of my issue.
That was very good work. Well Done.