Modern Vespa

I own a MP3 300. I had an incident and I had to repair all the cable on the right side. I did so. All the lights are working. Horn too. However when I try to start the engine, the anti-theft LED remains on all the time and nothing happens. The engine doesn't roll at all. During the incident, the leg shield is damaged right where the key is. Might have I damaged the antenna of immobilizer or it might be another problem? Battery in very good shape. Thank you in advance

Is very possible that antenna is damaged or is out of position and can't read the key. The question is, after yo turn the key to the on position, the immobilizer light goes off and continue to be off? or goes off and after some seconds is on? This is a good indicator if the problem is at the immobilizer. From your text looks as it remains on.

Try put the other key very close (touching) the antenna after you turn the primary key to the on position, if continue the same, check all the cables between the antenna and the ECU for continuity and if continuity is ok the only remaining is the antenna

thx a lot. I'll check and see how it goes.