The F3C6 disconnecting error in The Outlast Trials usually occurs when the game loses connection to the servers. This can happen due to unstable internet, server issues, firewall restrictions, or outdated game files.
To fix it, check your internet connection, restart the game and router, disable VPN or firewall temporarily, and make sure the game is updated to the latest version. If the servers are down, waiting and reconnecting later may resolve the issue.