https://wpt.fyi/results/webdriver/tests/classic/switch_to_frame/switch.py?label=experimental&label=master&aligned imported/w3c/webdriver/tests/classic/switch_to_frame/switch.py::test_frame_id_null Failure: ... with pytest.raises(NoSuchElementException): > element2.text ... > raise err E webdriver.error.StaleElementReferenceException: stale element reference (404): Node with identifier 'node-A596F74D-D118-456D-B540-E1741C4A6D0B' was not found Changed in WPT by https://phabricator.services.mozilla.com/D101065 (Bug 1684827 - [wdspec] Fix switch to frame tests for "no such element" error instead of "stale element reference".) > Element references are per browsing context. As such elements as found within a frame are not existent in any parent browsing context, and when retrieving these a "no such element" error has to be returned.