Knowledge Base

Problem

After transferring a project originally analyzed in an older EthoVision version (e.g., XT 17) to a newer version (e.g., XT 18), videos that play correctly in VLC Media Player produce playback errors within EthoVision. The experiment file and videos are otherwise intact.

Details

The error is caused by a codec or video decoder conflict that arises when EthoVision's internal video components are not correctly registered, particularly after a version transfer or upgrade. Because the videos play in VLC (which uses its own codec stack), the issue is specific to EthoVision's DirectShow/codec chain rather than the video files themselves. Reinstalling EthoVision re-registers the required components.

Solution

1. Confirm the video files are not corrupted by verifying playback in VLC Media Player.
2. Uninstall EthoVision XT from the PC (Control Panel → Programs → Uninstall).
3. Reinstall EthoVision XT using the correct version installer (available from MyNoldus or a direct link from Noldus support).
4. After reinstallation, reopen the transferred project and test video playback within EthoVision.
5. If the error persists after reinstallation, check for third-party codec packs (e.g., K-Lite) installed on the PC, as these can conflict with EthoVision's video components. Remove any third-party codec packs and retest.
6. If videos are in a format that EthoVision does not natively support, convert them to a compatible format (e.g., uncompressed AVI or H.264 AVI) before importing.