This error message might be caused by third-party detection software conflicting with Hackshield and its background processes. If you have any antivirus, anti-malware, or firewall programs installed, please temporarily disable them. Then, relaunch both Steam and CSN to see if you can play without any interruptions.
Additionally, if you usually have a lot of background programs running, such as download managers, try playing for 15-20 minutes with all non-essential programs closed to check if it resolves the error.