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current update prevents firefox from starting

  • 7 replies
  • 1 has this problem
  • 14 views
  • Last reply by FredMcD

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After applying the current update, Firefox will not launch. It was set to run as administrator. However, after clicking YES to the Windows10 pop-up prompt to allow Firefox to run as administrator, the Windows 10 pop-up prompt keeps coming up and Firefox will not launch. I cannot uncheck the RUN AS ADMIN from the PROPERTIES window. Help please … ASAP!!

After applying the current update, Firefox will not launch. It was set to run as administrator. However, after clicking YES to the Windows10 pop-up prompt to allow Firefox to run as administrator, the Windows 10 pop-up prompt keeps coming up and Firefox will not launch. I cannot uncheck the RUN AS ADMIN from the PROPERTIES window. Help please … ASAP!!

Chosen solution

FredMcD - I appreciate your perserverance and efforts to help me.

However and as I'd indicated earlier, my problem is not related to any security/firewall programs. This problem happen on all of my devices (PC, laptop & Surface) immediately after Firefox's recent update to v71.0. I think that this update process corrupted some files which would not allow it to run as Administrator. Apparently, an uninstall and full install fixes/replaces these bad files.

Holding back on this update on my remaining PC has kept it free of this problem. I wanted to keep this PC as a working backup while I figured out how to fix the other devices.

As I've indicated, I pretty much resolved the problem via numerous uninstalls and reinstalls ... and reapplying my original Firefox profile.

On my laptop, the problem came back after a day and required a 3rd uninstall and reinstall to bring it back. Wierdly and after this last uninstall/reinstall iteration on my laptop, I am able to launch Firefox as Adminis trator without any problems. So, out of curiosity, I did another uninstall and reinstall on my PC to see if it would allow Firefox to run as administrator. It did and still does.

Thanks again for your efforts. This post can be considered closed.

Read this answer in context 👍 0

All Replies (7)

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Some problems occur when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again;

  • Make sure your Internet security software is up-to-date (i.e. you are running the latest version).
  • Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see

Configure firewalls so that Firefox can access the Internet. {web link}

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All security programs (Norton & Spybot) were updated prior to allowing Firefox to update itself. The problem is NOT Firefox unable to connect to the internet. As I'd stated, Firefox will NOT LAUNCH after current Firefox update was applied.

I did the usual steps of uninstalling Firefox, after I backed up my profile file. Then, I re-installed Firefox, which launched successfully. However, Firefox will NOT start in ADMINISTRATOR mode ... which I can live with.

After, deleting the new/default profile and renaming my backed up profile. Firefox is back to the way that it was before crashing on me.

This problem happened on my other devices as well and has been a major pain to figure out and fix. Firefox support can do much better in testing out their updates before unleashing them with problems.

The Contributor's reply did NOT help to resolve my problem.

However, this post can be considered as CLOSED.

I'm not a happy camper :-(

Modified by vj000000

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What version of Firefox is this?

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Chosen Solution

FredMcD - I appreciate your perserverance and efforts to help me.

However and as I'd indicated earlier, my problem is not related to any security/firewall programs. This problem happen on all of my devices (PC, laptop & Surface) immediately after Firefox's recent update to v71.0. I think that this update process corrupted some files which would not allow it to run as Administrator. Apparently, an uninstall and full install fixes/replaces these bad files.

Holding back on this update on my remaining PC has kept it free of this problem. I wanted to keep this PC as a working backup while I figured out how to fix the other devices.

As I've indicated, I pretty much resolved the problem via numerous uninstalls and reinstalls ... and reapplying my original Firefox profile.

On my laptop, the problem came back after a day and required a 3rd uninstall and reinstall to bring it back. Wierdly and after this last uninstall/reinstall iteration on my laptop, I am able to launch Firefox as Adminis trator without any problems. So, out of curiosity, I did another uninstall and reinstall on my PC to see if it would allow Firefox to run as administrator. It did and still does.

Thanks again for your efforts. This post can be considered closed.

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That was very good work. Well Done. Please flag your last post as Solved Problem as this can help others with similar problems.