Navigate to your local installation directory, which typically defaults to C:\Program Files\Smart Professional Surveillance System\SmartPSS .
Locate a known working dhnetsdk.dll file. This usually comes bundled with the latest official standalone software packages from manufacturer support sites.
If you recently upgraded your hardware (DVR or NVR) or swapped an IP camera, your older computer software might not comprehend the recorder's commands. Smart PSS Error Help | IP Cam Talk
SmartPSS requires deep access to local network ports to query massive database files (video footage) from the recorder. Right-click the on your desktop. Select Run as administrator .