The error arises in this code
File “/home/frappe/frappe-bench/apps/frappe/frappe/desk/doctype/event/event.py”, line 22, in validate
self.validate_overlap()
File “/home/frappe/frappe-bench/apps/frappe/frappe/desk/doctype/event/event.py”, line 43, in validate_overlap
validate_overlap_for(self, “Event”, “teacher”)
hence your post here Overlap validation
It seems the query is malformed due to encoding?
Perhaps confirm tabTeacher in fact has this Alaa_Badri
“AttributeError: ‘teacher’ object has no attribute ‘translate’”