When a teacher tries to edit the course settings, it finds an exception when the teacher role does not have the moodle/course:changesummary capability. This capability is enabled by default but it is possible that some sites disabled it for some client policies.

Exception - Argument 1 passed to file_get_all_files_in_draftarea() must be of the type integer, null given, called in [dirroot]/lib/form/filemanager.php on line 336

More information about this error

×Debug info: 

Error code: generalexceptionmessage

×Stack trace:

line 767 of /lib/filelib.php: TypeError thrown

line 336 of /lib/form/filemanager.php: call to file_get_all_files_in_draftarea()

line 580 of /lib/formslib.php: call to MoodleQuickForm_filemanager->validateSubmitValue()

line 526 of /lib/formslib.php: call to moodleform->validate_defined_fields()

line 636 of /lib/formslib.php: call to moodleform->is_validated()

line 156 of /course/edit.php: call to moodleform->get_data()

Further Investigation

This bug seems to be introduced by MDL-62849 and the root of this problem is the type declaration defined in function file_get_all_files_in_draftarea. In this definition, it is forced to receive $draftitemid as an int value but for this scenario, $draftitemid is null causing the exception to the user. Before the change on MDL-62849, the function that did this process was file_get_drafarea_files that does not have any type declaration.