5 Common Ad Errors & How to Fix Them

5 Common Ad Errors & How to Fix Them

One of the most common concerns I hear from publishers is about the mysterious ad error codes that they sometimes receive when trying to serve a video ad. Ad error codes show up as anonymous numbers when ad playback is interrupted, and contain little to no information on causes or possible resolutions.

With some research and experimentation, as well as some help from our friends at 
WatchingThat, below is a list of the five most frequent video ad errors. While there is rarely just one foolproof solution to resolving each error, I have included advice on possible resolutions for each of the error codes. It is important to keep in mind that not all ad errors are made equal, and not all are necessarily fatal to the ad serving process.

Error 303 - No Ads VAST Response After One or More Wrappers

This error is perhaps the one most frequently experienced by publishers. Error 303 indicates that no valid ad was returned after the player and SDK followed the wrappers in the ad response. This error is somewhat “expected,” it simply indicates that the third party is not able to fill the given ad request. The number of 303 errors should roughly match the expected percentage of your inventory that your ad provider does not expect to fill. In other words, if a third party’s expected fill is 70%, 30% of your requests may return this error. The best way to remedy this situation, outside of speaking to your ad providers about ways to increase demand, would be to create a fallback/passback in DFP. This will ensure that, in the worst case scenario, you will at least have a house ad to fall back to when there is no demand.

Error 301 - Timeout of VAST URI

Error 301 indicates that a URI within the VAST or VPAID creative timed out. This could be due to errors on requests, such as an invalid or unreachable URI, and security exceptions related to HTTP/HTTPS. The most common reason for Error 301 is a poor network connection or heavy latency.

The first step would be to check the URI within the VAST/VPAID creative to make sure it is valid and reachable. This can easily be done by copy and pasting it into the browser address bar and following the redirect. A broken URI would definitely trigger error 301. Another factor is if the ad creative is using a mix of HTTP/HTTPS URLs, or perhaps attempting to serve insecure HTTP creative to a secure HTTPS webpage. The SSL protocols must match.

Finally, determine which platform this error occurs most frequently. If the issue is largely on mobile, make sure your pages are well optimized for mobile traffic. This can be done by reducing the size of the images, lazy loading, caching, and making sure the ad integration is not being prevented from rendering by other page elements.

Error 302 - Wrapper Limit Reached

This error is caused by daisy chaining, or overly complex advertising logic. The IAB recommends that no more than five wrapper redirects be used in an ad response, the IMA3 SDK has a limit of four by default. This can be manually raised if Error 302 is detected, however, we recommend speaking to your ad providers about enforcing the lower number of wrappers, as a first step. A higher number of redirects will make for a poor user experience as well as added latency.

Error 402 - Timeout of Media File URI

Error 402 is caused by the ad creative taking longer to load than your current timeout setting and is directly related to the type or size of media file used within the VAST or VPAID ad unit. The error implies that the file is either too large, the bitrate is too high, or it is incompatible with the platform on which it is attempting to render.

Steps you can take to reduce these errors include increasing the request timeout, optimizing your website to increase load speed, and most importantly, setting bitrate and size restrictions on creatives serving on mobile.

Error 901 - General VPAID Error

This famous (infamous?) error is every publishers’ favorite one. It is notoriously vague and can imply multiple problems related to VPAID. There are multiple possible causes, so it can be difficult to pinpoint the exact steps to address them. Issues may include Flash trying to serve on HTML5, VPAID opt outs, and viewability solution wrappers that do not deliver an MP4 or other linear media file.

When you encounter Error 901, the first thing to check is whether you are attempting to use the 
VPAID adaptor instead of Brightcove’s IMA3 SDK plugin. When generating the tag in DFP, you can elect to use this adaptor which essentially creates the IMA SDK layer for the purpose of displaying the VPAID or rely on the Brightcove player. Since in the majority of cases you will already be using our IMA3 SDK, you will not need the adaptor option. Trying to play the adaptor tag in the IMA3 plugin will lead to duplication, resulting in Error 901.

This is not the only possible solution. Other things to check include making sure the VPAID is not Flash, inquiring with the ad provider about opt-outs, and verifying that the VPAID tag works in a test environment (such as theGoogle VAST tester).


While this article does not include every possible ad error and resolution that you may encounter, it should give you a leg up on some of the most frequent problems publishers experience. The most important thing to consider is you cannot resolve a problem that you aren’t able to identify in the first place, and that is where tools such as the one provided by Brightcove’s new partner, WatchingThat, can help you.

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