Since the version 2.0, the default video preview format is no longer Flash, but MP4, chosen for the compatibility of video playback on the mobile devices.

The change is in the workflow wf_CreateVideoPreview.xml.

Bug fixing

This change causes a jerky preview on client computers in builds prior to 2126. Tera provided a fix in parsers in the build 2.0.2126 and newer (tracking reference GN4-2103). Install it and the rebuild previews for all videos, or in the meantime, you may want to return to the Flash preview.