diff --git a/stock/doctype/serial_no/serial_no.py b/stock/doctype/serial_no/serial_no.py
index 35308bce17..190b92be3f 100644
--- a/stock/doctype/serial_no/serial_no.py
+++ b/stock/doctype/serial_no/serial_no.py
@@ -65,9 +65,9 @@ class DocType(TransactionBase):
 	# validate
 	# ---------
 	def validate(self):
-		import utilities
-		utilities.validate_status(self.doc.status, ["In Store", "Delivered", 
-			"Not in Use", "Purchase Returned"])
+		# import utilities
+		# utilities.validate_status(self.doc.status, ["In Store", "Delivered", 
+		# 	"Not in Use", "Purchase Returned"])
 
 		self.validate_warranty_status()
 		self.validate_amc_status()
diff --git a/website/helpers/product.py b/website/helpers/product.py
index 1e8257a7a7..623ceeee34 100644
--- a/website/helpers/product.py
+++ b/website/helpers/product.py
@@ -102,4 +102,5 @@ def get_parent_item_groups(item_group_name):
 		
 def invalidate_cache_for(item_group):
 	for i in get_parent_item_groups(item_group):
-		delete_page_cache(i.page_name)
\ No newline at end of file
+		if i.page_name:
+			delete_page_cache(i.page_name)
\ No newline at end of file
diff --git a/website/utils.py b/website/utils.py
index ec33103e29..674d752114 100644
--- a/website/utils.py
+++ b/website/utils.py
@@ -263,7 +263,8 @@ def clear_cache(page_name=None):
 		webnotes.cache().delete_keys("page:")
 	
 def delete_page_cache(page_name):
-	webnotes.cache().delete_value("page:" + page_name)
+	if page_name:
+		webnotes.cache().delete_value("page:" + page_name)
 	
 def url_for_website(url):
 	if url and not url.lower().startswith("http"):