There's a sensor so the motorbike knows when you're holding the clutch.
It is located under the clutch lever assembly, more or less like the brake light switch is under the front brake lever.
(I'm sorry my English is not good enough to properly explain myself!
)
I would check that, as it seems it can be prone to get loose and the bike won't start if it is not where it should be.
Hope it's nothing more serious than that!