Speedy is correct. Details of the following police classifications include: Blue LED's, Blue lights on the roof of any variant.
The only light you may use at all is the pilot light which is the yellow one with the word pilot on it.
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That with us assuming you downloaded the new version either yesterday or today. One thing I happen to notice is I used to launch it and let it redirect me to their website, but this update will not redirect you from launching the game. It'll disconnect you to offline status. So you have to go to the TruckersMP website yourself and hit download.
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If none of this is solving your issue, then a support ticket would probably be the next step to follow, so it can be assisted by someone quicker who has access to more information than we do.
http://truckersmp.com/support/
Visit that website and simply click on Submit A Ticket