PRO TIP:If the issue is with your computer or a laptop/notebook you should try using Fortect Repair which can scan the repositories and replace corrupt and missing files. This works in most cases, where the issue is originated due to a system corruption. You can download Fortect byClicking...
"description":"URL to a valid Arma 3 basic.cfg file. The\"Basic\"configuration file is used during server runtime for advanced network performance tuning. Because it is a required file, this URL is used to download it during installation, or if the file is found missing during startup."...