We're sorry to hear that Firefox is crashing. In order to assist you better, 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.)

Thank you for your help!

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

No crash reports present, as Firefox lets the phone rebooting there is no message or report. There are other report on the net witch are exactly the same as mine. Nexus phones on marshmallow rebooting while watching a movie on Firefox.

No log file present as the phone reboots. I am not the only one with this problem. It has been reported also with the Nexus 5x.

I switched to chrome which doesn't has this issue.

We have a new version of Firefox for Android with a fix for the Marshmallow (Android 6.0) reboot on media playback. https://www.mozilla.org/en-US/firefox/android/42.0.1/releasenotes/

This solved my issues with firefox playing videos on some websites, stuttering, freezing and rebooting my Nexus 7 2013 Wifi and Marshmallow. Good job guys!