Motorcycle and Scooter appreciation

Background:
Bike: 2015 Scrambler EFI

• The bike was knocked over and there was damage to:
  o Speedo bracket
  o Clutch hand leaver
  o Clutch foot peg
  
• I replaced the clutch foot peg two weeks ago, and I can’t remember but I’m sure I started the bike after to check it all worked. It hasn’t been run since though.
  
• I can’t remember when but at some point I took the speedo off to work out what to do about it and put it back on, all plugged in.
  
• Last week I put the missing gaitors back on by taking the calliper, wheel, mudguard (fender) off then sliding the shocks out and putting it all back together.
  
• Today I replaced the bent aftermarket clutch hand leaver with a non-OEM stock one.
  
• After installing I went to check the adjustment and tried to start the bike, but it wouldn’t start.
  
• I have plugged in an optimate.
  
  

Problem:
Bike won’t start.
I turn the key in the ignition, hold the clutch down, press the ignition switch nothing happens – there is no noise, and it doesn’t turn on.
When turning the key the starter lights come on as they should but the Engine Management System Malfunction Indicator Light(?) comes on and stays on. Although thinking about it I’m sure it’s always on until the engine turns over.

Question:
Any ideas?
Or more to the point where do I start to identify what the actual issue is.
I have a volt meter (which I need to remember how to use). I have a Haynes manual - which I also need to work out how to use, it doesn’t feel very intuitive.

other possibly(?) relevant info
No side stand.
I don’t know if this is of any significance, but the front right indicator wasn’t working and the rear right was blinking at the wrong speed. I Noticed the right wing mirror mount wasn’t straight, so I straightened it and made sure all the connections were tight and the combination resolved.

Cheers!