I don't think it's related. They were removing XBL piece by piece for a quite some time now. /r/firefox has many mosts about such removals. Anyway - nightly is

I don't think it's related. They were removing XBL piece by piece for a quite some time now. /r/firefox has many mosts about such removals. Anyway - nightly is a dev build. It is expected to have bugs of all kinds.