...
Restart the program, then machine - Fixes most issues, as restarting the machine will grab any software updates that are missing. If this does not fix missing programs or outdated software, see Software Installation Issues and Troubleshooting.
Make sure everything is connected and plugged in
Unplug and plug the machine back into the power bar/outlet - General fix for when a power surge occurs and the machine does not start up when the power button is pressed.
...