Hey Spark team,
Just wanted to let you know I had an odd issue with /build. It was working fine (thanks for the multiple file option by the way!). Then when I went back to it yesterday I just get a blank page.
Digging through the dev console I can see a whole bunch of permission denied errors:
I also tried going to /login and /signup - same thing.
In the end I deleted any cookies you had set and was able to get to the login page and everything worked again. Not sure what the actual issue was but thought I should let you know.