hello onlyus, the firefox aurora release channel has been converted into the firefox developer edition. your data hasn't be erased but the dev edition starts with a separate profile by default. in order to get back to your old data, please refer to Recover lost bookmarks on Firefox Developer Edition

The the version of Aurora channel changed from 35.0.a2 to 36.0.a2 on Nov 28 so you should have seen it as Developer Edition since.

This channel and Nightly gets checkins almost everyday so therefore there is a update each of those days.