Note that crash report IDs that do not start with 'bp-' have not been submitted and thus are of no use (invalid). If a line on the about:crashes page doesn't start with "bp-" then click the line to submit the report and the link will be updated and gets a "bp-" prefix if the report is submitted successfully. --- Signature of the second crash report: *Firefox 40.0.2 Crash Report [@ igdumd32.dll@0xf9280 ] 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 Signature of the first crash report: *Firefox 40.0.3 Crash Report [@ RtlpCallQueryRegistryRoutine | RtlExitUserThread | hcapi.dll@0x41ea ] You can check for issues with MacAfee software (hcapi.dll is a process belonging to the McAfee Host Intrusion Prevention program).