I'm trying to create an External Tool Assignment on Moodle v3.9.2. But as soon as I am choosing "External Tool" option in "Add an activity or resource" menu, I am being redirected to "/course/modedit.php?add=lti&type=&course=2§ion=1&return=0&sr=0" page with message:
Exception - Argument 1 passed to mod_lti\local\ltiservice\service_base::set_instance_form_values() must be an instance of mod_lti\local\ltiservice\object, instance of stdClass given, called in [dirroot]/mod/lti/mod_form.php on line 366
Unfortunately could not find this issue already described anywhere.
Could anyone give a piece of advice on what to do now?