Ah I think I found the problem with that linux error at least (filename case sensitivity issue), pushing up a fix for that atm.
For mac, I'd unfortunately need more info. If you're familiar enough with JS to tinker with it, you could try modifying the "login" function in App.js to try and narrow down where things are going wrong. We can see it's disabling the button and never re-enabling it, so the catch block and none of the "failLogin" lines are being reached, but I'm not sure where it's getting stuck.