Troubleshoot VAST tag problems

VAST (Video Ad Serving Template) tags use the XML (eXtensible Markup Language) format. XML is a text-based format for representing structured information. If the XML file used by the VAST tag is empty, invalid, or has syntax errors, your creative will be rejected.

Step 1: Preview the creative

If you have have access to Display & Video 360, follow these steps:

1. Open the creative.
2. On the "Details" tab, click Preview. The preview opens in a new window. The video player loads with a placeholder video of a person driving a car.
3. Click play to preview your video ad. If your preview plays, you can close the preview and look for problems in the XML file.
4. If there's a problem with your video ad, you'll only see the placeholder video play. Contact your ad server and ask them to fix the video creative.

If you don't have access to Display & Video 360, but you do have the VAST tag, follow these steps:

1. Open the Video suite inspector.
2. Select Vast tag for the input type.
3. Click Test Ad.

Step 2: Check the XML file used by your VAST tag

Follow the steps below to read the XML file and look for problems.

1. Copy the VAST tag URL from your creative.
2. Open a blank browser tab.
3. Paste the copied URL in the browser's address bar and press Enter. The XML file will load. If the tag is wrapped, you
4. You should be able to see the following details in the XML:
   • VAST version
   • Video duration
   • Impression or event tracking
   • Media files with dimensions, format, and bit rate
     Example VAST XML
5. If the XML file includes a line with <Wrapper>, the tag is wrapped, and the file you're looking at is the wrapper. Copy the URL you see below <VASTAdTagURI>, this is the original VAST tag. Repeat steps 3 and 4.

Step 3: Check for common problems

VAST tag is invalid or empty

If you can preview the creative without any problems, and the XML file loads in a browser, there might be a problem with the VAST that's causing it to look empty or an error in the file that's causing a problem that's not visible in the preview.

Contact your ad server and ask them to fix the video creative.

Creative doesn't work without cookies

If the creative uses cookies, it needs to have a default ad that can serve when cookies are turned off, or the creative will be rejected.

Use an incognito window to check if the creative doesn't work without cookies

Note: This test will only work the first time you load the file. If you refresh the window, you are likely to have the missing cookie, and the XML will load.

1. Copy the VAST tag URL from your creative.
2. Open an incognito window in your browser.
3. Paste the copied URL in the address bar of the incognito window and press Enter. The XML file will load.
4. If the XML file is empty, then the creative may be using cookies. Cookies are commonly needed when using targeting criteria like sequential rotation, frequency caps, or audience segmentation.
   • If the creative isn't hosted in Campaign Manager 360, contact your ad server and ask them to fix the video creative to make sure it works when cookies are turned off.
   • If the video creative is hosted in Campaign Manager 360, open the synced Campaign Manager 360 placement and add a default in-stream video ad. If you prefer not to use default ads, you can add an ad with no targeting to the placement and assign it a low priority. This ad will serve when cookies are turned off. After you fix the creative, allow about an hour for the updated creative to sync to Display & Video 360.

Problems with synced Campaign Manager 360 campaign

If the creative is synced from Campaign Manager 360:

1. In Display & Video 360, open the creative and copy the CM360 ID.
2. Open Campaign Manager 360 and paste the ID in the search bar.
3. Press Enter to search, then open the placement.
4. Make sure the creative and ad are assigned to the placement and that all 3 are active. If they're not active, set them to active.
5. Make sure the start date of the placement, creative, and ad are not in the future. If they are, set them to the current time so they can start serving.
6. Make sure the site, campaign, and advertiser are active and none of them have an "on hold" status. If the advertiser is on hold, set it to approved, then activate its ads.
7. Save your changes, then wait about an hour for the updates to sync to Display & Video 360.