User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:37.0) Gecko/20100101 Firefox/37.0 Build ID: 20150328222441 Steps to reproduce: 1. Open Firefox and go to any site (for example this bug report) and cause Firefox to crash. 2. Repeat opening Firefox and crashing it until about:sessionrestore is showed. Actual results: Firefox does often not show about:sessionrestore on a restart after browser.sessionstore.max_resumed_crashes + 1 crashes. Expected results: Firefox should show about:sessionrestore on a restart after browser.sessionstore.max_resumed_crashes + 1 crashes. Additional information: On my current tests it looked like waiting a little after Firefox got restarted after a crash happened before causing the next crash reduces the chance of this issue to appear. Also it looked like browser.sessionstore.max_resumed_crashes set to 0 works always as expected. Could it be that the number of crashes/restarts is counted too late so that the information is lost if the next crash appears too early?