It could be the work of one of your add-ons. Type about:addons<enter> in the address bar to open your Add-ons Manager. Hot key; <Control>(Mac=<Command>)<Shift> A)

In the Add-ons Manager, on the left, select Extensions. Disable a few add-ons, then Restart Firefox.

Some added toolbar and anti-virus add-ons are known to cause Firefox issues. Disable All of them.

If the problem continues, disable some more (restarting FF). Continue until the problem is gone. After, you know what group is causing the issue. Re-enable the last group ONE AT A TIME (restarting FF) until the problem returns.

Once you think you found the problem, disable that and re-enable all the others, then restart again. Let us know who the suspect is, detective.

In Firefox Safe mode these changes are effective:

• all extensions are disabled (about:addons)
• default theme is used (no persona)
• default toolbar layout is used
• xulstore.json is ignored
• userChrome.css and userContent.css are ignored (chrome folder in profile folder)
• JavaScript JIT compilers are disabled
• hardware acceleration is disabled (Options > Advanced > General)

• plugins are not affected
• preferences are not affected

There are other things that need attention.

Your System Details list shows that you have a user.js file in the profile folder to initialize prefs each time Firefox starts. The user.js file will only be present if you or other software has created this file and normally won't be present.

You can check its content with a plain text editor (right-click: "Open with"; do not double-click). The user.js file is read each time Firefox is started and initializes preferences to the value specified in this file, so preferences set via user.js can only be changed temporarily for the current session.

You can delete the user.js file if you didn't create this file yourself. You can use this button to go to the current Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Sorry but that didn't work. Still not responding, just in safe mode. I removed the user.js. Anymore ideas please.

I just turned on acrobat, it open but scroll just a little bit and it locks up acrobat? Not responding. That's in or out of FF.

What is firefox patch.exe 6/21/16

Where did you get that? Mozilla does not use exe to do updates.

. Whenever you get a message / popup that software / files need to be updated;

DO NOT USE ANY OF THE PROVIDED LINKS

While this may be a legitimate message, it could also be Malware or a Virus. Any time you want or need to check for upgrades, go to the website of the True Owner of the program in question. For example, to check out Firefox, go to https://www.mozilla.org {web link}

You can report such a site at; Google Report Phishing Page {web link} which is the same when done while on site by going to Help > Report Web Forgery

Help us safeguard Mozilla’s trademarks by reporting misuse {web link}

GeneWo said

What is firefox patch.exe 6/21/16

Probably malware or a virus looking to infect your PC.

Mozilla doesn't "patch" Firefox, it releases updates. And an .exe only works on Windows; Firefox is made to work on Windows plus Mac plus Linux plus a few arcane operating systems. The Firefox updates are delivered directly to Firefox via a .mar file and gets installed automatically by Firefox on the local PC - not offered to the user to save and then install themselves.

How do I get FF 48.0?

The current is

• 1 Download Firefox For All languages And Systems v47 {web link}
• 2 Uninstall Firefox from your computer {web link}
  DO NOT remove your profiles.
• 3 After, reboot the computer. Then run the full installer.

I tried something like that, but this does seem to work. Thank you.

You can try to disable hardware acceleration in Firefox.

• Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"

You need to close and restart Firefox after toggling this setting.

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

You can check if there is an update for your graphics display driver and check for hardware acceleration related issues.

• https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

Create a new profile to test if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

FredMcD said

It could be the work of one of your add-ons. Type about:addons<enter> in the address bar to open your Add-ons Manager. Hot key; <Control>(Mac=<Command>)<Shift> A) In the Add-ons Manager, on the left, select Extensions. Disable a few add-ons, then Restart Firefox. Some added toolbar and anti-virus add-ons are known to cause Firefox issues. Disable All of them. If the problem continues, disable some more (restarting FF). Continue until the problem is gone. After, you know what group is causing the issue. Re-enable the last group ONE AT A TIME (restarting FF) until the problem returns. Once you think you found the problem, disable that and re-enable all the others, then restart again. Let us know who the suspect is, detective.

As soon as I re-enabled Flash on my v47.0, FF became non-responsive. Am now downgrading as I'm too fed up of having to use FF in Safe Mode all the time.

Fixed. But have problems with adobe acrbat DC locking up, their board doesn't seem to help?

If you have problems with current Shockwave Flash plugin versions then check this:

• see if there are updates for your graphics drivers

https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

• disable protected mode in the Flash plugin (Flash 11.3+ on Windows Vista and later)

https://forums.adobe.com/message/4468493#TemporaryWorkaround

• disable hardware acceleration in the Flash plugin

https://forums.adobe.com/thread/891337 See also:

• http://kb.mozillazine.org/Flash#Troubleshooting