If the test video works but you don't see any ads yet, try reloading the page. If you continue to not see the video it may be because:
Your site's users are not in target with the available campaigns at this time. Read Which ads will be visible on my site
You are using a browser that's not supported.
The browsers supported for the Test Units are Google Chrome desktop and mobile, Internet Explorer and Mozilla Firefox.
The code is not compatible with your platform (Wordpress, Wix, etc.) or with your Ad Manager (DFP)
If you are viewing pages that use Google AMP technology from a mobile or mobile viewer, check that you have used our compatible AMP code <amp-ad>
You activated the Test Unit from a different device from than the one you're currently looking at. Log in to Viralize and activate the Test Units from the device you're testing
If you're still not seeing the demo video, the code you have copied is incorrect (contains errors) or it was copied and pasted in an invalid location on the page, outside the <body> tag.
Read Where should I embed the Unit code on my Site?