I install the latest build and after try to login the existing app (safari), it went into some issue checking the console found some JS bug on some line, then try to comment that piece of line and it works fine after.
Now, as Jaymer said it does not appear at his end I tried again by uncommenting the last change and seems not it does not present the same issue.
It seems to be flaky as not able to produce again.
So, no worries at this time.