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I get an error stating - "A breakpoint has been reached (ox.800000003) occurred in the application at location ox70551aa1. Click on OK to terminate program.

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Since the Firefox 39 update both mine and my girlfriend computers have both been getting the same message and same things happening. Both our computer freeze up. Where the pointer has changed to a blue circle going around continually. In the task bar we see that --> Firefox in not responding. Microsoft Outlook is not responding. Microsoft Word is not responding. Microsoft Excel is not responding. When trying to end process nothing happens. Then the message box pops up. The top of the message box says Plugin-container.exe. In the message box it says "A breakpoint has been reached (ox.800000003) occurred in the application at location ox70551aa1. Click on OK to terminate program." ((Locations vary)). When you click the OK nothing happens. Even trying to restart or shutdown computer takes forever and basically does not happen. We have to push and hold the power button on the computer. This happens up to 10+ times a day. The sad thing was as I was typing this in Firefox my computer froze and I was just lucky enough to be able to copy and paste what I am typing into Microsoft Word and save it before my computer crashed because everything was not responding. I had to push and hold the power button on the computer. Once I was back running I continued typing in Word and will paste into the Firefox support. This happens even when Firefox is the only program running.

Since the Firefox 39 update both mine and my girlfriend computers have both been getting the same message and same things happening. Both our computer freeze up. Where the pointer has changed to a blue circle going around continually. In the task bar we see that --> Firefox in not responding. Microsoft Outlook is not responding. Microsoft Word is not responding. Microsoft Excel is not responding. When trying to end process nothing happens. Then the message box pops up. The top of the message box says Plugin-container.exe. In the message box it says "A breakpoint has been reached (ox.800000003) occurred in the application at location ox70551aa1. Click on OK to terminate program." ((Locations vary)). When you click the OK nothing happens. Even trying to restart or shutdown computer takes forever and basically does not happen. We have to push and hold the power button on the computer. This happens up to 10+ times a day. The sad thing was as I was typing this in Firefox my computer froze and I was just lucky enough to be able to copy and paste what I am typing into Microsoft Word and save it before my computer crashed because everything was not responding. I had to push and hold the power button on the computer. Once I was back running I continued typing in Word and will paste into the Firefox support. This happens even when Firefox is the only program running.

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Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac Options)
key, and then starting Firefox. Is the problem still there?


Start your Computer in safe mode with networking. Then start Firefox. Try Safe web sites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

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Do you recall what kind of plugin-based content might have been playing at the time of the crash, such as Flash video, Silverlight video, etc.?

The plugin content might or might not have caused the freeze, there's no way to know at this point. However, while you are troubleshooting this, it might be helpful, to avoid unnecessary pain on sites where Flash is not actually essential, try setting Flash to Click-to-Play ("Ask to Activate"). This will delay Flash from starting on a page until you approve it.

To set "Ask to Activate", open the Add-ons page using either:

  • Ctrl+Shift+a
  • "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. Look for "Shockwave Flash" and change "Always Activate" to "Ask to Activate".

When you visit a site that wants to use the Flash, you should see a notification icon in the address bar and usually (but not always) one of the following: a link in a black rectangle in the page or an infobar sliding down between the toolbar area and the page.

If you see a good reason to use Flash, and the site looks trustworthy, you can go ahead and click the Lego-like icon in the address bar to allow Flash. You can trust the site for the time being or permanently.

But some pages use Flash only for tracking or playing ads, so if you don't see an immediate need for Flash, feel free to ignore the notification! It will just sit there in case you want it later. For troubleshooting purposes, I would allow as little Flash as possible to see whether that makes any difference.


Did you ever modify how Firefox handles unresponsive scripts? Some users tire of having to click off dialogs and change the timeout so that scripts can run longer before the dialog appears. This can cause Firefox to freeze up for extended periods.

One common cause of unresponsive script errors on Windows 7 and newer is the protected mode feature of the Flash player plugin. That feature has security benefits, but seems to have serious compatibility issues on some systems. There is a hidden setting to disable it; I suggest trying this for a day to see whether it helps:

(A) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(B) In the search box above the list, type or paste flash and pause while the list is filtered

(C) Double-click the dom.ipc.plugins.flash.disable-protected-mode preference to switch its value from false to true.

This might not take effect until all Flash has been unloaded for a few minutes, or you close Firefox.