If a video won't play for participants, it's almost always about where the video lives and who can reach it — not Knowly itself. Knowly shows the video from wherever you linked or uploaded it, so playback depends on that source, the participant's network, and their browser.
Check it as a participant first
Preview the activity as a participant, not as an admin. Many problems come from a video that's shared with you but not with everyone, and a preview reproduces exactly what participants see.
Common causes
Sharing permissions. If you pasted a link to a video hosted elsewhere — Microsoft Stream, a Google Drive video, an intranet page — it needs to be shared with everyone in the journey, not just you. This is the most common cause. For Microsoft Stream, see Troubleshooting Microsoft Stream videos in Knowly.
Network or firewall restrictions. Some workplace networks block streaming or specific video providers. If it plays at home but not at the office, the network is the likely cause.
An embed that isn't supported. Paste the URL of the video's page from a major provider such as YouTube or Vimeo, or a proper embed code. A private, expired, or region-locked link won't play.
Browser or privacy settings. Strict privacy settings or browser extensions can block embedded players. Trying another browser quickly rules this in or out.
If you uploaded the file to Knowly
A video you uploaded to Knowly doesn't depend on outside sharing. If it doesn't play right after upload, give it a moment to finish processing, then reload the page. For accepted formats and sizes, see File limits and accepted formats.