Amphtml: AMP broken in IE11

[robinac30]

What's the issue?

AMP is no longer working in IE11 as of this morning

How do we reproduce the issue?

View https://amp.dev/ in Internet Explorer v11

What browsers are affected?

Internet Explorer v11 and below

Which AMP version is affected?

New issue which was picked up by our visual regression testing.

Seeing this in console:

Could not locate https://raw.githubusercontent.com/ampproject/amphtml/2004142326360/src/polyfills/src/polyfills/custom-elements.js specified in source map https://cdn.ampproject.org/v0.js.map.

[7110]

amp-img can't work on IE by released 2004142326360

I'm rushing to deal with by the way to lock versions of AMP runtime and components
https://twitter.com/innovate_7110/status/1240144750432452609

[uskay]

@choumx This seems urgent. Can we consider a rollback?

[jkurzend]

seems amp4ads banner ads do not work anymore. IE11: up to ~5% marketshare. One could easily make the math. Could'nt you consider a rollback?

[sebastianbenz]

@7110 it's better to fallback to the LTS version (which is supported by the AMP validator) https://github.com/ampproject/amphtml/blob/master/contributing/lts-release.md

[rcebulko]

The console error may be unrelated to page breakages; that's a known issue with the source map generation, but it shouldn't impact the runtime files.

[caroqliu]

These are the errors found when reproducing on amp.dev with IE 11.719:

The page is missing all of its assets:

[nainar]

This issue should be fixed in 2004030010070. This is the current stable.

Please accept my apologies for the inconvenience this issue has caused you all.

We will be keeping this issue open to track the cause since we have just done a revert for now.

[jridgewell]

@nainar is correct that 2004030010070 fixes the issue. Unfortunately, LTS is 012004142326360 (the broken version). LTS is 2004030010070, and the recommended way to fix the bug for now.

[rcebulko]

We can update LTS to 2004030010070 with minimal impact, usage is still fairly low

[danielrozenberg]

@jridgewell LTS is at 2004030010070 as well right now - maybe you have the opt-in cookie set? :)

[jridgewell]

Apologies, LTS is currently 2004030010070. I had an opt-in cookie overriding the LTS version.