Reach to grab revenue

Common VAST Error Codes and How to Resolve Them

Publishers have struggled with VAST error codes because they disrupt video ad serving, costing them money and effort. We will explore the realm of VAST error codes in this post, learning what they are and how to fix them. Both deadly and non-fatal common VAST errors will be broken down, along with their respective explicit fixes. By the conclusion, you’ll have a thorough grasp of these mistakes and the means to deal with them successfully.

The Growing Importance of Video Advertising

Subscribe to our newsletter

Understanding the importance of video advertising can help us better comprehend VAST error codes. By the end of 2022, online videos will account for 82% of consumer internet traffic, predicts Cisco. Users enjoy video content, giving it an ideal platform for publishers to include advertisements and increase revenue. 244.4 million people in the US alone watch digital videos, with viewers aged 18 to 24 making up 97.8% of the audience. 54% of customers worldwide say they want to watch video content from their favorite brands, indicating a growing desire for this type of media.

What is a VAST Error?

VAST Errors, also known as video ad-serving template errors, are bugs that can happen when delivering digital video ads. These mistakes can halt the replay of an advertisement, preventing the audience from hearing the intended message. A number code is provided when a VAST error occurs. Whether or not the video ad plays again depends on the sort of fault.

  • Non-fatal errors: These errors allow the video player to continue playing the ad, though there may be issues.
  • Fatal errors: Fatal errors force the video player to either request another ad or abandon the failed ad request.

Common VAST Error Codes and Their Resolution (Fatal Errors)

1. VAST Error 100 – XML Parsing Error

How to Resolve:

This error occurs due to issues like invalid XML documents, distorted buyer responses, or failed VAST URL redirects.

1. Notify the buyer to verify the XML file’s format and ensure it contains all relevant attributes as per the VAST specification of IAB.

2. VAST Error 102 – Response Version Not Supported

This error happens when the video player doesn’t support the specified VAST version or when the exchange mistakenly sends the wrong version.

How to Resolve:

1. Make the buyer aware to send only supported VAST formats.

3. VAST Error 300 – Wrapper Error

Wrapper errors occur when the wrapper limit is reached, rendering it unactionable.

How to Resolve:

1. Review all VAST URIs (Unified Resource Identifier) to ensure they do not time out and remain accessible.

2. Ensure the wrapper limit is not exceeded.

4. VAST Error 301 – Redirect Timeout Reached

This error signifies a timeout of the VAST URI, often caused by an unresponsive or faulty URI within a VAST creative.

How to Resolve:

1. Check the validity of the VAST URI.

2. Verify the internet connection for potential faults.

3. Address protocol issues, ensuring URI is hosted and served consistently (HTTP vs. HTTPS).

5. VAST Error 302 – Wrapper Limit Reached

This error appears when the wrapper limit has been surpassed due to excessive wrapper responses without an inline response.

How to Resolve:

1. Collaborate with SSPs or publishers to increase the wrapper limit.

2. Avoid daisy chaining (passing ad calls from one network to another) to reduce redirects.

6. VAST Error 303 – Empty VAST Response Returned

This error occurs when an empty VAST response is returned, often within a third-party wrapper.

How to Resolve:

1. Enable fallback in Google Ad Manager:

   – Sign in to your Google Ad Manager account.

   – Click on Admin >> Video >> Video Settings.

   – Enable Video Fallback.

   – Click Save.

7. VAST Error 402 – Unable to Download or Timeout of MediaFile URI

This error signifies a timeout when a media file experiences issues, often due to large size or platform incompatibility.

How to Resolve:

1. Optimize website layouts to increase page load speed.

2. Increase the video player’s timeout limit.

3. Adjust the bitrate for mobile serving.

8. Bonus: General VPAID Error

VPAID errors, like Error 901, are common in video advertising and can result from various factors.

Possible Causes:

  • Use of an IMA Adapter Tag in Ad Exchange with the IMA SDK but receive a VPAID ad instead.
  • VPAID wrapper timeout.
  • VPAID wrapper not purchasing video files.

How to Resolve:

1. Ensure VPAID creatives are supported across all devices and video players.

2. Check compatibility in Google Ad Manager.

A List of All the VAST Error Codes

For a comprehensive list of VAST error codes and their meanings, refer to the [IAB’s wiki for VAST error codes](

How to Create a VAST Error Report through GAM?

Creating a VAST error report in Google Ad Manager involves a seven-step process:

1. Go to the “Reporting” tab, click “Report,” and select “New Report.”

2. Set the report type to “Historical” with a date range.

3. Add report dimensions, including line item type, line item name, and ad unit name.

4. Select metrics like “Total Code Served Count,” “Total Impressions,” and “Third-Party Networks responded to an ad request.”

5. Include the option “Total Error Count” under “Video Viewership.”

6. Select all error codes under “Video Errors.”

7. Run your VAST Error Report.

Best Practices for Publishers to Follow

While troubleshooting VAST errors is essential, the best approach is to prevent them from occurring in the first place. Here are some best practices for publishers:

1. Collaborate with partners (SSPs, DSPs, ad networks) to improve VAST creative performance.

2. Ensure DSPs scan creatives beforehand to catch issues early.


Understanding VAST errors is crucial for improving the performance of your video ads. Armed with knowledge about their causes and resolutions, you can prevent these errors from disrupting your advertising campaigns and enhance the user experience.

Frequently Asked Questions

Q1) What is VAST?

VAST (Video Ad Serving Template) is a script that enables video players and ad servers to run video ads. It provides publishers with control over which ads to serve, ad duration, and skippability, among other parameters.

Q2) What are VAST Errors?

VAST errors are codes indicating issues with the Video Ad Serving Template (VAST) standard and its implementation. These errors can signify problems with ad delivery, compatibility, and more.

Q3) What are Some Common VAST Errors?

Some of these common errors include VAST Error 100 (XML parsing error), VAST Error 200 (VAST ad tag empty or invalid), VAST Error 300 (General Wrapper error), and VAST Error 400 (General Linear error).