Change the character '1' to '0' (w/o quotes), saves it then restart the game. Disabling speedo in-game by pressing Tab+1 only disable the display not the operation so it won't solve the problem. I'm sorry for the inconvenience, it will be corrected soon.
The game stops when after switching a vehicle to RC heli (if "RC_spawn" mod installed) or vice-versa. The cause probably from switching display between the DIAL & DIGITAL speedometer. To overcome this error for the meantime, disable either the
DIGITAL or the DIAL speedo in "1speed.ini" configuration file using a text editor. Look for the line --> Speed_U2 = 1 Speed_U = 1