I got this error when trying to compile and download the file to my computer, all the time
Error del servidor: no se ha podido realizar la compilación. ¡Por favor, inténtalo de nuevo más tarde!
It means the MIT build servers are VERY busy and are at capacity. You can try again to build you apk in a few minutes and frequently your app will compile. Please be patient; there are LOTS of users building apps.
MIT is currently running 15 build servers; they added 3 the other day to help with the congestion.