🚨 Error: Null promise in layoutCallback

[ampprojectbot]

Details

Error report: link
First seen: Apr 8, 2020
Frequency: ~ 3,986,683/day

Stacktrace

Error: Null promise in layoutCallback
    at Error (https://raw.githubusercontent.com/ampproject/amphtml/2004252135000/src/log.js:714:16)
    at createErrorVargs (https://raw.githubusercontent.com/ampproject/amphtml/2004252135000/src/log.js:308:20)
    at apply (https://raw.githubusercontent.com/ampproject/amphtml/2004252135000/src/log.js:323:18)
    at dev (https://raw.githubusercontent.com/ampproject/amphtml/2004252135000/extensions/amp-a4a/0.1/amp-a4a.js:1090:8)
    at attemptToRenderCreative (https://raw.githubusercontent.com/ampproject/amphtml/2004252135000/extensions/amp-a4a/0.1/amp-a4a.js:1075:11)
    at layoutCallback (https://raw.githubusercontent.com/ampproject/amphtml/2004252135000/src/custom-element.js:1151:39)
    at fn (https://raw.githubusercontent.com/ampproject/amphtml/2004252135000/src/utils/promise.js:75:12)
    at https://raw.githubusercontent.com/ampproject/amphtml/2004252135000/src/utils/promise.js:74:9
    at tryResolve (https://raw.githubusercontent.com/ampproject/amphtml/2004252135000/src/custom-element.js:1151:22)

Notes

@rsimha modified src/log.js:308-311 in #21212 (May 16, 2019)
@erwinmombay modified src/log.js:323-324 in #6581 (Dec 20, 2016)
@keithwrightbos modified extensions/amp-a4a/0.1/amp-a4a.js:1089-1091 in #9039 (Apr 29, 2017)
@glevitzky modified extensions/amp-a4a/0.1/amp-a4a.js:1072-1086 in #9535 (Jul 18, 2017)
@zhouyx modified src/custom-element.js:1150-1151 in #15410 (May 18, 2018)
@jridgewell modified src/utils/promise.js:75-78 in #15143 (May 8, 2018)
@zhouyx modified src/custom-element.js:1150-1151 in #15410 (May 18, 2018)

Possible assignees: @zhouyx, @jridgewell

[rcebulko]

Resurfacing of #21116; closing as a dupe, but linking to add stacktrace/blame context