diff --git a/erpnext/controllers/selling_controller.py b/erpnext/controllers/selling_controller.py
index 606cc908669..2a22b32637b 100644
--- a/erpnext/controllers/selling_controller.py
+++ b/erpnext/controllers/selling_controller.py
@@ -330,7 +330,7 @@ class SellingController(StockController):
 		self.make_sl_entries(sl_entries)
 
 	def set_po_nos(self):
-		if self.doctype in ("Delivery Note", "Sales Invoice"):
+		if self.doctype in ("Delivery Note", "Sales Invoice") and hasattr(self, "items"):
 			ref_fieldname = "against_sales_order" if self.doctype == "Delivery Note" else "sales_order"
 			sales_orders = list(set([d.get(ref_fieldname) for d in self.items if d.get(ref_fieldname)]))
 			if sales_orders:
diff --git a/erpnext/education/report/course_wise_assessment_report/course_wise_assessment_report.py b/erpnext/education/report/course_wise_assessment_report/course_wise_assessment_report.py
index 5badda6565a..ce581486ec3 100644
--- a/erpnext/education/report/course_wise_assessment_report/course_wise_assessment_report.py
+++ b/erpnext/education/report/course_wise_assessment_report/course_wise_assessment_report.py
@@ -245,5 +245,5 @@ def get_child_assessment_groups(assessment_group):
 		assessment_groups = [d.get("value") for d in get_children("Assessment Group",
 			assessment_group) if d.get("value") and not d.get("expandable")]
 	else:
-		assessment_groups = [args.assessment_group]
+		assessment_groups = [assessment_group]
 	return assessment_groups
diff --git a/erpnext/patches/v10_0/update_hub_connector_domain.py b/erpnext/patches/v10_0/update_hub_connector_domain.py
index fc3c29403f4..808ae77129f 100644
--- a/erpnext/patches/v10_0/update_hub_connector_domain.py
+++ b/erpnext/patches/v10_0/update_hub_connector_domain.py
@@ -1,8 +1,9 @@
 import frappe
 
 def execute():
-    frappe.db.sql("""
-        UPDATE `tabData Migration Connector`
-        SET hostname = 'https://hubmarket.org'
-        WHERE connector_name = 'Hub Connector'
-    """)
\ No newline at end of file
+	if frappe.db.table_exists("Data Migration Connector"):
+		frappe.db.sql("""
+			UPDATE `tabData Migration Connector`
+			SET hostname = 'https://hubmarket.org'
+			WHERE connector_name = 'Hub Connector'
+		""")
\ No newline at end of file