The original 2016 Firefox release schedule had the release of Firefox 49 shipping on September 13, 2016. During our release qualification period for Firefox 49, we discovered a bug in the release that causes some desktop and Android users to see a slow script dialog more often than we deem acceptable. In order to allow time to address this issue, we have rescheduled the release of Firefox 49 to September 20, 2016.

In order to accommodate this change, we will shorten the following development cycle by a week. No other scheduled release dates are impacted by this change.

In parallel, Firefox ESR 45.4.0 is also delayed by a week.