🚨 Error: Assertion failed

Details
---
**Error report:** [link](http://go/ampe/CKOMo-enpImtAw)
**First seen:** Mar 4, 2021
**Frequency:** ~ 32/day

Stacktrace
---

Error: Assertion failed

    at message (src/core/assert.js:92:29)

    at getElementsByClassName (src/service/owners-impl.js:137:34)

    at getElementsByClassName (src/service/owners-impl.js:137:34)

    at src/service/owners-impl.js:129:35

    at getResourceForElement (src/service/owners-impl.js:82:43)

    at this (extensions/amp-consent/0.1/consent-ui.js:383:8)

    at resume (extensions/amp-consent/0.1/amp-consent.js:178:22)

    at reset (src/custom-element.js:1524:20)

    at src/utils/signals.js:56:4

    at doWork (src/service/resources-impl.js:1839:43)

    at src/service/task-queue.js:87:4

    at measure (src/service/resources-impl.js:754:18)

    at Input (src/input.js:32:13)

    at delay (src/pass.js:94:36)

    at src/service/timer-impl.js:125:24

Notes
---
`@rcebulko` modified `src/core/assert.js:92-93` in [#32887](https://github.com/ampproject/amphtml/pull/32887) (Feb 25, 2021)
`@lannka` modified `src/service/owners-impl.js:118-155` in [#24222](https://github.com/ampproject/amphtml/pull/24222) (Aug 30, 2019)
`@lannka` modified `src/service/owners-impl.js:118-155` in [#24222](https://github.com/ampproject/amphtml/pull/24222) (Aug 30, 2019)
`@lannka` modified `src/service/owners-impl.js:118-155` in [#24222](https://github.com/ampproject/amphtml/pull/24222) (Aug 30, 2019)
`@powerivq` modified `src/service/owners-impl.js:78-84` in [#23668](https://github.com/ampproject/amphtml/pull/23668) (Aug 26, 2019)
`@dvoytenko` modified `extensions/amp-consent/0.1/consent-ui.js:366-392` in [#32480](https://github.com/ampproject/amphtml/pull/32480) (Feb 8, 2021)
`@dvoytenko` modified `extensions/amp-consent/0.1/amp-consent.js:168-181` in [#32480](https://github.com/ampproject/amphtml/pull/32480) (Feb 8, 2021)
`@dvoytenko` modified `src/custom-element.js:1524-1527` in [#7312](https://github.com/ampproject/amphtml/pull/7312) (Feb 17, 2017)
`@dvoytenko` modified `src/utils/signals.js:55-56` in [#23951](https://github.com/ampproject/amphtml/pull/23951) (Aug 14, 2019)
`@lannka` modified `src/service/resources-impl.js:1836-1840` in [#24622](https://github.com/ampproject/amphtml/pull/24622) (Sep 20, 2019)
`@dvoytenko` modified `src/service/task-queue.js:43-95` in [#3544](https://github.com/ampproject/amphtml/pull/3544) (Jun 14, 2016)
`@muxin` modified `src/service/resources-impl.js:751-754` in [#7327](https://github.com/ampproject/amphtml/pull/7327) (Feb 17, 2017)
`@dvoytenko` modified `src/input.js:27-45` in [#226](https://github.com/ampproject/amphtml/pull/226) (Sep 18, 2015)
`@cramforce` modified `src/pass.js:94-94` in [#3904](https://github.com/ampproject/amphtml/pull/3904) (Jul 6, 2016)
`@jridgewell` modified `src/service/timer-impl.js:125-125` in [#5758](https://github.com/ampproject/amphtml/pull/5758) (Oct 24, 2016)

**Seen in:**
- 03-04 Nightly (0444)

**Possible assignees:** `@rcebulko`, `@dvoytenko`

/cc @ampproject/release-on-duty

Start with the stack trace in src/service/owners-impl.js, then trace the calls from extensions/amp-consent/0.1/consent-ui.js and extensions/amp-consent/0.1/amp-consent.js; use the linked error report for reproduction details. Done means identifying the cause of the assertion failure and verifying that this reported error no longer occurs.

Written by the indexing model from the issue text.