1. Enter about:crashes in the Firefox address bar and press Enter. A list of Submitted/Unsubmitted Crash Reports will appear, similar to the one shown below.
2. Copy the 5 most recent Submitted 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.)

Thank you for your help!

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

Hi plumage, sorry to hear about the crashes and thank you for submitting reports. To get specific assistance, you can share some recent reports with forum volunteers to see whether we recognize how to solve the problem. Please check the support article "Firefox crashes - asking for support" for steps to get those crash report IDs from the about:crashes page, and then post some of the recent ones here.

These are the 5 most recent reports:

bp-54697308-f695-4cf1-9853-2bb790190101 bp-e329ca31-ab44-4b8b-a360-588a90190101 bp-4fdce1b2-5709-4ab8-b966-10c7b0190101 bp-345e70f1-3117-4b64-9816-828e80190101 bp-919a13bd-341b-4129-b660-c61060190101

thx.

Thanks. All five has the same "signature": "IPCError-browser | ShutDownKill". But:

• in 2 reports, Firefox shut down in 13-15 seconds
• in 3 reports, Firefox shut down after 7 hours and 14 minutes and 1 second, +/-10 seconds

That's both startlingly consistent and inconsistent.

Do you have any reports for Firefox 64, in case they possibly provide more clues?

Here is one example:

bp-9f99a479-86da-4c3a-bc3a-068110181214

Thanks. This is another IPC error:

IPCFatalErrorMsg : "Error deserializing 'data' (SerializedStructuredCloneBuffer) member of 'ClonedMessageData'"

IPC refers to interprocess communications, which is how the browser process exchanges messages with the processes running web content.

I still can't tell what is causing it, however, whether it is triggered by something in a page running in one of your tabs, or by external software (such as AVG), or is a "sleep/wake" problem that sometimes affects Windows users. Do you notice any pattern to it?