When the cars in the server don't move try adjusting the dynamic track settings in the server_cfg.ini file.

The following settings should work:
[DYNAMIC_TRACK]
SESSION_START=95
RANDOMNESS=2
SESSION_TRANSFER=90
LAP_GAIN=10

Please restart the server after changing the above settings and see if the cars move correctly.

If they still don't move you may want to adjust the following settings:
In the entry list.cfg file, set for each vehicle:
BALLAST=0 

In the server_cfg.ini set the following:
MAX_BALLAST_KG=0
LEGAL_TYRES=V;E;HR;ST

LOOP_MODE=1
ALLOWED_TYRES_OUT=2 
DAMAGE_MULTIPLIER=100 
FUEL_RATE=100 
TYRE_WEAR_RATE=100