HLDS Updater
If you have the latest version of the HLDS Updater installed on your server̵7;s host computer, you can download and apply patches to dedicated servers hosting games provided by Valve Corporation̵7;s Steam gaming network. The Tools section, found on the bottom navigation bar of all pages in the Steam store, contains the download link.
Command Line Entry
The HLDS Updater requires command line entry to begin its processes. This may be unfamiliar to people more comfortable with graphics-based user interfaces, and the entry required to update Gmod dedicated servers must be typed in precisely. After opening a command prompt on your Windows or Linux installation and entering the directory for your Gmod installation, you can type in this command to initialize the update: hldsupdatetool -command update -game garrysmod -dir.
Verify Network Connection
Gmod files available through Steam require a valid Internet connection, as verified by your router and Internet settings, and your firewall must allow the HLDS Updater to communicate with outside servers. Steam maintains extensive files on network troubleshooting to assist you with locating the cause of connectivity problems. Failure to connect may also occur if the Steam servers are down for maintenance or otherwise unavailable.
Additional Information
Multiple issues can cause the HLDS Updater and local Steam clients to crash during updates. Your host computer should be running the latest version of its operating system, including any service packs or similar updates, and your network security protocols must be set to allow external connections. Some anti-virus programs and security suites may interfere with the normal workings of the HLDS Updater and Steam client tools, but disabling or uninstalling these programs should help to prevent crashes.