For example when /grade/edit/outcome/edit.php editing a scale I get the following. Check all gradebook admin pages to make sure they all are.
Coding problem: this page does not set $PAGE->context properly.
- line 339 of /lib/pagelib.php: call to debugging()
- line 1219 of /lib/pagelib.php: call to moodle_page->magic_get_context()
- line 1126 of /lib/setuplib.php: call to moodle_page->initialise_theme_and_output()
- line ? of unknownfile: call to bootstrap_renderer->__call()
- line 1209 of /lib/formslib.php: call to bootstrap_renderer->pix_url()
- line 147 of /lib/formslib.php: call to MoodleQuickForm->MoodleQuickForm()
- line 109 of /grade/edit/outcome/edit.php: call to moodleform->moodleform()