double check your settings inside the config.yml file in the "steam:" section, open it with notepad
you should have compiled like this:
install_path:C:\Program86\Steam\steamapps\common\assettocorsa\server
(obviously this is my path, you have to put your own)
# the path to the executable to run. relative to install_path by default
executable_path: acServer.exe
# set this to true to force an install every time the server manager is loaded
force_update: false
usually the problems are due to the path "install_path:" being incorrect or not filled in
it seems difficult the first few times but then it isn't, but every step must be respected.
Remember that if you don't open the ports in your router that you use for the ac server and acserver, the server won't work.
The correct compilation of the config.yml file is very important, check that you have correctly entered your path where you have the acServer.exe executable.
and check that you assigned the ports correctly and that they are open in the router.
UDP_PORT = 9600
TCP_PORT = 9600
HTTP_PORT = 8081
these three ports must be open in the router, they are the ports that assettocorsa and "acservermanager" use.