fix: prev_doc
diff --git a/erpnext/hr/doctype/employee/employee.py b/erpnext/hr/doctype/employee/employee.py
index d407945..3fc330e 100755
--- a/erpnext/hr/doctype/employee/employee.py
+++ b/erpnext/hr/doctype/employee/employee.py
@@ -216,7 +216,7 @@
 			doc.db_set("employee", self.name)
 
 	def reset_employee_emails_cache(self):
-		prev_doc = self.get_doc_before_save()
+		prev_doc = self.get_doc_before_save() or {}
 		cell_number = self.get('cell_number')
 		prev_number = prev_doc.get('cell_number')
 		if (cell_number != prev_number or