Bug: Intermittent browser/base/content/test/outOfProcess/browser_basic_outofprocess.js | Uncaught exception - at chrome://mochitests/content/browser/browser/base/content/test/outOfProcess/head.js:75 - TypeError: content.document.getElementById(...) is null
Status: RESOLVED
Priority: P5
Resolution: DUPLICATE
Created: 2021-04-26 15:15:53+00:00
Resolved: 2022-07-26 16:54:08+00:00

**Filed by:** archaeopteryx [at] coole-files.de
**Parsed log:** https://treeherder.mozilla.org/logviewer?job_id=337724160&repo=try
**Full log:** https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/Mt_ww7M2SJ6ln4bIqB-Zvg/runs/0/artifacts/public/logs/live_backing.log

---
```
[task 2021-04-26T12:41:41.219Z] 12:41:41     INFO - TEST-START | browser/base/content/test/outOfProcess/browser_basic_outofprocess.js
[task 2021-04-26T12:41:41.567Z] 12:41:41     INFO - TEST-INFO | started process screencapture
[task 2021-04-26T12:41:41.874Z] 12:41:41     INFO - TEST-INFO | screencapture: exit 0
[task 2021-04-26T12:41:41.874Z] 12:41:41     INFO - Buffered messages logged at 05:41:41
[task 2021-04-26T12:41:41.874Z] 12:41:41     INFO - Entering test bound test_subframes_string
[task 2021-04-26T12:41:41.874Z] 12:41:41     INFO - Console message: [JavaScript Error: "The character encoding of the HTML document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the page must be declared in the document or in the transfer protocol." {file: "https://example.com/browser/browser/base/content/test/outOfProcess/file_base.html" line: 0}]
[task 2021-04-26T12:41:41.874Z] 12:41:41     INFO - Console message: [JavaScript Error: "Unknown Collection "main/partitioning-exempt-urls"" {file: "resource://services-settings/RemoteSettingsClient.jsm" line: 160}]
[task 2021-04-26T12:41:41.874Z] 12:41:41     INFO - UnknownCollectionError@resource://services-settings/RemoteSettingsClient.jsm:160:5
[task 2021-04-26T12:41:41.874Z] 12:41:41     INFO - sync@resource://services-settings/RemoteSettingsClient.jsm:470:13
[task 2021-04-26T12:41:41.874Z] 12:41:41     INFO - 
[task 2021-04-26T12:41:41.874Z] 12:41:41     INFO - Console message: [JavaScript Warning: "The character encoding of a framed document was not declared. The document may appear different if viewed without the document framing it." {file: "https://www.mozilla.org/browser/browser/base/content/test/outOfProcess/file_innerframe.html" line: 0}]
[task 2021-04-26T12:41:41.874Z] 12:41:41     INFO - Console message: [JavaScript Warning: "The character encoding of a framed document was not declared. The document may appear different if viewed without the document framing it." {file: "https://test1.example.org/browser/browser/base/content/test/outOfProcess/file_innerframe.html" line: 0}]
[task 2021-04-26T12:41:41.875Z] 12:41:41     INFO - Buffered messages finished
[task 2021-04-26T12:41:41.875Z] 12:41:41     INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/outOfProcess/browser_basic_outofprocess.js | Uncaught exception - at chrome://mochitests/content/browser/browser/base/content/test/outOfProcess/head.js:75 - TypeError: content.document.getElementById(...) is null
[task 2021-04-26T12:41:41.875Z] 12:41:41     INFO - Stack trace:
[task 2021-04-26T12:41:41.875Z] 12:41:41     INFO - @chrome://mochitests/content/browser/browser/base/content/test/outOfProcess/head.js:75:1
[task 2021-04-26T12:41:41.875Z] 12:41:41     INFO - execute@resource://specialpowers/SpecialPowersSandbox.jsm:141:12
[task 2021-04-26T12:41:41.875Z] 12:41:41     INFO - _spawnTask@resource://specialpowers/SpecialPowersChild.jsm:1604:15
[task 2021-04-26T12:41:41.875Z] 12:41:41     INFO - receiveMessage@resource://specialpowers/SpecialPowersChild.jsm:310:21
[task 2021-04-26T12:41:41.875Z] 12:41:41     INFO - Leaving test bound test_subframes_string
```