Let's try to find out exactly why Firefox is crashing.

Please follow the steps below to provide us crash IDs to help us learn more about your crash.

1. Enter about:crashes in the Firefox address bar and press Enter. A Submitted Crash Reports list will appear, similar to the one shown below.
2. Copy the 5 most recent Report IDs that start with bp- and then go back to your forum question and paste those IDs into the "Post a Reply" box.

Note: If a recent Report ID does not start with bp- click on it to submit the report.

(Please don't take a screenshot of your crashes, just copy and paste the IDs. The below image is just an example of what your Firefox screen should look like.)

More information and further troubleshooting steps can be found in the Troubleshoot Firefox crashes (closing or quitting unexpectedly) article.

And if Firefox won't stay open long enough to view about:crashes you can retrieve your Crash Report ID's like this:

1. On the keyboard, press [Windows] The image "Windows key" does not exist. + [R]. This should bring up a Run window that contains a text field.
2. In that text field, type %APPDATA% and press Enter. An explorer window should open.
3. From that explorer window, double-click on the Mozilla folder, then double-click on Firefox and then on Crash reports. Double-click on submitted.
4. Now, you should see a list of files that contain reports. Go to View > Arrange Icons by > Modified to get the most recent files at the top of the window.
5. Open the most recent 5 files with a text editor and copy the IDs.
6. Paste each ID with bp- into the reply window on the forums.

Thanks in advance!

You can find more information and troubleshooting steps in the Troubleshoot Firefox crashes (closing or quitting unexpectedly) article.

Thanks for your help! Here are the 5 most recent crashes -- Report ID Date Submitted bp-311c624f-daa0-473d-8a5a-9474c2160226 2/26/2016 10:13 AM bp-2ee0bd79-269e-4e08-8d61-4582d2160226 2/26/2016 10:13 AM bp-52f4b338-cfe3-482f-b152-65f3b2160226 2/26/2016 10:13 AM bp-03cf0650-6214-462d-b48e-eeace2160226 2/26/2016 10:13 AM bp-6712c180-4768-4a2e-8860-655842160226 2/26/2016 10:12 AM

Hope this helps you.

All 5 of those crash reports red flag this DLL as the 'trigger' of those crashes. AppleFFDAV.dll

http://systemexplorer.net/file-database/file/appleffdav-dll "This files most often belongs to product iCloud Control Panel."

Disable the extension that it installed for Firefox for now. firefoxdav@icloud.com

Check for an update for that application or for that extension for Firefox to allow you to keep using it with Firefox and not cause that type of crash.

That extension is not on my list of installed extensions so I can't disable it.

Did you check for an update for that iCloud Control Panel application? If there's an update, that might fix that crashing problem.

View one of those Crash Reports and look the the Extensions tab - it shows 4 extensions - firefoxdav@icloud.com is at the bottom.

Sorry, I don't understand why the Crash reporter picked up the presence of that extension on your system, but it doesn't appear for you in Firefox. I was of the belief that Firefox didn't allow Plugin extensions to be available in Firefox and remain hidden from view in the Add-ons Manager panel; new one on me.

Those crash reports are from before I refreshed Firefox. It doesn't crash when I don't sign in to my Firefox account. If I just close that login window, I can continue using Firefox without problems. I guess I'll just continue to do that.

I really do appreciate your help!

I'm getting closer to fixing this, I think. I just reinstalled a couple of plugins - Shockwave Flash and Adblock Plus. Then I did a Sync. About 30 minutes later Firefox crashed and kept crashing with each restart until it gave me the option to start in safe mode. I did that and checked the addons and I saw the iCloud bookmarks and the Theme and Font Changer add-ons so I removed them, along with a couple other add-ons that I don't use much. I restarted Firefox and it seems to be working again.

Is it the Sync function that keeps reloading those "bad" add-ons?

Edit - you posted again while I was composing this reply.

Any chance that you are posting here using a different PC that to one you are having this crashing problem on? I an seeing both as running Firefox 44.0.2 on Windows 10, between the More System Details here and what is shown in those 5 Crash Reports.

But the PC you first posted here with shows on disabled extension; not the 4 active extensions that the Crash Reports show. And only one of those 4 can be readily identified by the "Extension Id".

Those Crashes which appear to have happened after you started this thread at 10am CST TODAY. Unless you are in different time zone than I am [CST] - and the Crash Times have a different 'offset' from UTC on your PC than what I see in this forum. Which could easily explain the difference in what I am seeing.

And now you mention doing a Refresh after those crashes? I don't see that mentioned in any prior posting in this thread.

If Firefox is still crashing after doing that Refresh? If so, how about some new Crash Reports from after that Refresh?

Forgetting about trying to help you solve your Crashing problem ... As far as deleting your Sync account, you can login here - https://accounts.firefox.com/signup and at the bottom use Have an account? Sign in. to sign in - and change your Account Password, which will wipe your data from only the Sync server, and not affect your "local data" - on your devices. Or delete your Firefox account.

More of the edit

Yes, Sync can reinstall those add-ons if that option is selected in Sync preferences. And being that the iCloud extension was installed as part of an "external application", that extension could get re-installed automatically upon a Windows re-start or "cold-boot".

Ed, you've got the patience of a saint. Sorry I didn't mention that I have two PCs that are both crashing. Here are the latest 5 crash reports from the main PC that I am posting from. And I'm in EST zone. Report ID Date Submitted bp-cd557cd5-7328-4aaa-a1bf-3ac512160226 2/26/2016 4:26 PM bp-9b61ebd8-2e70-4a36-88d5-d81a22160226 2/26/2016 4:26 PM bp-19dae26d-9d3e-4c29-b505-adb032160226 2/26/2016 4:25 PM bp-11b73ebe-b67b-434b-8948-bb8062160226 2/26/2016 4:25 PM bp-5a6640fc-8131-4402-a351-34af02160226 2/26/2016 4:24 PM

I was doing a refresh after every crash - that was the only way I could get Firefox to work. I didn't realize that I could start it in safe mode and delete add-ons. I just figured that out a couple of hours ago (sorry, I'm slow...)

Firefox is not crashing at the moment on either PC since I have deleted that iCloud add-on. I've reinstalled the Theme and Font Changer add-on to this PC and it seems to be stable so far.

Thanks for the info about deleting the Sync account. If I crash again, I'll do that. And again, thanks for your patience.

That could be a problem with the iCloud Bookmarks extension (firefoxdav@icloud.com) that show under the extensions in the crash report.

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

• Bug 1097138 - startup crash in appleffdav.dll

That seems to have been the problem. Thanks for that troubleshooting link. I've bookmarked it for the future. Wish I'd found it sooner!