If you are already running version 4.0 or higher, you may be able to update manually without a full reflash: EmuELEC 4.3 - Update Guide [EEMC204]
Standard EmuELEC boots to a black screen for 2 minutes. The patched version is faster, but you must do one thing immediately.
Release the button once the EmuELEC splash screen appears; the system will then automatically resize partitions and reboot.