[ReneG]

I don't know if you did this on purpose, but the function you are calling in SetTimer doesn't match the function at the bottom of your script.

pawn Код:

SetTimerEx("TrailerCheck" // blah blah

public TC(playerid)
// same thing for the LevelUp function as well.

One is TrailerCheck the function is TC. They have to be the same.

Also, in the command /confirmtruck.

pawn Код:

new vehicle = GetPlayerVehicleID(playerid);

The way you are using it, it should be

pawn Код:

new vehicle = GetVehicleModel(GetPlayerVehicleID(playerid));

Vehicle ID is the server-sided vehicle ID.