diff --git a/erpnext/accounts/report/accounts_receivable/accounts_receivable.py b/erpnext/accounts/report/accounts_receivable/accounts_receivable.py
index 76f51ee4c2..e4ae2a4698 100644
--- a/erpnext/accounts/report/accounts_receivable/accounts_receivable.py
+++ b/erpnext/accounts/report/accounts_receivable/accounts_receivable.py
@@ -38,7 +38,7 @@ class ReceivablePayableReport(object):
 				"width": 120
 			})
 
-		columns += [_("Age (Days)") + "::80"]
+		columns += [_("Age (Days)") + ":Int:80"]
 
 		if not "range1" in self.filters:
 			self.filters["range1"] = "30"
diff --git a/erpnext/controllers/taxes_and_totals.py b/erpnext/controllers/taxes_and_totals.py
index 0fbe22d7af..27ec6181b0 100644
--- a/erpnext/controllers/taxes_and_totals.py
+++ b/erpnext/controllers/taxes_and_totals.py
@@ -355,7 +355,7 @@ class calculate_taxes_and_totals(object):
 							item.net_amount = flt(item.net_amount + discount_amount_loss,
 								item.precision("net_amount"))
 
-					item.net_rate = flt(item.net_amount / item.qty, item.precision("net_rate"))
+					item.net_rate = flt(item.net_amount / item.qty, item.precision("net_rate")) if item.qty else 0
 
 					self._set_in_company_currency(item, ["net_rate", "net_amount"])
 
diff --git a/erpnext/selling/doctype/sales_order/sales_order.py b/erpnext/selling/doctype/sales_order/sales_order.py
index eda8c7323a..732867ff01 100644
--- a/erpnext/selling/doctype/sales_order/sales_order.py
+++ b/erpnext/selling/doctype/sales_order/sales_order.py
@@ -396,7 +396,7 @@ def make_sales_invoice(source_name, target_doc=None):
 				"parent": "sales_order",
 			},
 			"postprocess": update_item,
-			"condition": lambda doc: doc.base_amount==0 or doc.billed_amt < doc.amount
+			"condition": lambda doc: doc.qty and (doc.base_amount==0 or doc.billed_amt < doc.amount)
 		},
 		"Sales Taxes and Charges": {
 			"doctype": "Sales Taxes and Charges",
diff --git a/erpnext/stock/doctype/item/item.py b/erpnext/stock/doctype/item/item.py
index 310f4cca22..8a6acd7c77 100644
--- a/erpnext/stock/doctype/item/item.py
+++ b/erpnext/stock/doctype/item/item.py
@@ -200,8 +200,8 @@ class Item(WebsiteGenerator):
 			self.set("reorder_levels", [])
 
 		if self.re_order_level or len(self.get("reorder_levels", {"material_request_type": "Purchase"})):
-			if not self.is_purchase_item:
-				frappe.throw(_("""To set reorder level, item must be a Purchase Item"""))
+			if not (self.is_purchase_item or self.is_pro_applicable):
+				frappe.throw(_("""To set reorder level, item must be a Purchase Item or Prodcution Item"""))
 
 	def validate_warehouse_for_reorder(self):
 		warehouse = []