Amphtml: amp4ads-host-v0.js: b.postMessage is not a function error msg

[rokerkony]

What's the issue?

AMP is poluting our application logs in bugsnag. See more here:

How do we reproduce the issue?

Unfortunatelly I don't know.

What browsers are affected?

Is there something we could do? Our app has no intention to be on AMP :( at least for now

[aghassemi]

/to @lannka Looks like an in-a-box issue.

[lannka]

Might be cause by this code.

Pending messages are from external scripts. They might be passing wrong message data.

If so, this is legitimate errors we should bring up to ad networks who send those wrong messages.

Which ad network is your application using? Is it doubleclick?

[rokerkony]

Hey, we are using https://www.googletagservices.com/tag/js/gpt.js 👍

[lannka]

@keithwrightbos can you provide some insights for gpt.js? Is it possible for gpt.js to pass along wrong pending messages.

[rokerkony]

any progress here?

[twhid]

I'm also seeing the same errors. According to New Relic, it's 90.16% of my errors over the last 3 days and it's overwhelmingly Safari (both desktop and iOS). It's creating a lot of noise.

This is the script:
https://cdn.ampproject.org/rtv/011535566825959/amp4ads-host-v0.js

It doesn't appear to be a problem with the message, the error is that b.postMessage is undefined. Perhaps the handle on the iframe (which I assume is b) is being lost?

We're using doubleclick.

[lvillanne]

I'm also seeing same errors with users on safari/ios and chrome/ios.

We're using doubleclick.

[voidzone]

Getting a plethora of these too.

[cramforce]

@lannka Independent of the ad networks we should probably be robust against the null b value and if this is too spammy switch to a warning.

[iMontes]

Any progress?

[lvillanne]

This bug affect :

• All browser on IOS (Safari Mobile, Chrome Mobile, ...)
• Safari on Mac OS

In my case, this error is more than 90% of my javascript errors.

[cgdev332]

Is there an update for this...

[himberjack]

Watching...

[lannka]

will down grade it to a warning. self assigned

[lannka]

looked at code now, we have already added message validation (#15020) and try catch during message processing (#17749) long time ago. that said, we shouldn't expect the b.postMessage error as posted originally.

If this is still a problem, @himberjack @cgdev332 @lvillanne @iMontes could you provide a new stack trace to assist debugging?

[ababbdev]

We are still getting this as recent as 30 minutes ago.

TypeError: b.postMessage is not a function. (In 'b.postMessage(R("position",a.sentinel,d),c)', 'b.postMessage' is undefined) at qa(https://raw.githubusercontent.com/ampproject/amphtml/1812261943070/ads/inabox/inabox-messaging-host.js:182:5) at ? (https://raw.githubusercontent.com/ampproject/amphtml/1812261943070/ads/inabox/inabox-messaging-host.js:169:11) at ? (https://raw.githubusercontent.com/ampproject/amphtml/1812261943070/ads/inabox/position-observer.js:73:7) at fire(https://raw.githubusercontent.com/ampproject/amphtml/1812261943070/src/observable.js:84:7) at ? (https://raw.githubusercontent.com/ampproject/amphtml/1812261943070/ads/inabox/position-observer.js:64:9) at d(https://raw.githubusercontent.com/ampproject/amphtml/1812261943070/src/utils/rate-limit.js:39:5) at ? (https://raw.githubusercontent.com/ampproject/amphtml/1812261943070/src/utils/rate-limit.js:57:7)

Thanks for your attention to this matter.

[oguzhanaslan]

progress?

[alaa-awartany]

Thanks for your efforts, watching...