In short, don't bother installing the current Android N Developer preview version on your Nexus device. (nashvillechatterclass.com)
While the general public is receiving access to Android O beta for the first time, Android developers have had access to the first developer preview version for weeks now. (nashvillechatterclass.com)
However, Google has now released the fifth and final developer preview version of Android N, which -LSB-...] (nashvillechatterclass.com)