having made several different starting errors on my SE5 (yes, in just a week, what can i say, i am dedicated to make every error once!) here are my tips: (i know some of these have been covered before, but hey, here they are all in one post)
1. make sure you press M quickly (if you hold in M until the message disappear, it won't start) - i asked dealer about this before i got her home (due to repeatedly holding M down too long)
2. make sure foot brake is depressed - i found this out (can't remember if dealer told me) when trying to show to a friend who was sitting in saddle
3. make sure you are not pressing key down when your turn it
4. do NOT try to start, or press M, while initial diagnostics are still running. to combat this i have developed a routine, i turn key On, then get on Spyder, press down foot brake, disengage parking brake, then turn off engine kill, then check display, hit M, Start.
5. make sure engine kill switch is not engaged
6. (if applicable) make sure you have YOUR Spyder key, and not your SO's (this does not apply to many, including myself, but is included for completeness of the list)
i think those are all the errors i have committed (and the bonus one).
hopefully one of these is always the problem, if not, then get it checked by dealer....
oh, and for those who did not know on SE5 (at least the '11 model year) the clutch disengages the gear whenever your turn off engine (and it will continuously beep at you until you engage parking brake). so whenever you go to start an SE5 (again i have only ever rydden an '11) it will always be in N when you start it - or try to.