Knowledge Base

Problem

The camera image does not appear in EthoVision even though the camera is physically connected and detected in Pylon Viewer. Disabling the Windows firewall resolves the issue.

Details

Reported on Basler GigE cameras and potentially other network-connected cameras. The Windows firewall blocks the network traffic between EthoVision and the camera, preventing the live feed from displaying. The camera may appear as detected in Pylon but the image stream is blocked at the application level. Multiple users at the same institution have independently encountered this issue.

Solution

1. As a diagnostic step, temporarily disable the Windows Firewall (Control Panel → Windows Defender Firewall → Turn Windows Defender Firewall on or off) and retest the camera feed in EthoVision.
2. If the feed appears after disabling the firewall, re-enable the firewall and create an inbound/outbound exception rule for EthoVision.exe and Pylon-related processes.
3. Alternatively, work with your IT department to whitelist the GigE camera subnet or the specific ports used by Pylon/Basler camera communication.
4. Do not leave the firewall permanently disabled; always restore firewall protection after confirming the camera exception is working.