diff --git a/erpnext/setup/doctype/naming_series/naming_series.py b/erpnext/setup/doctype/naming_series/naming_series.py
index d97ce74..9af6295 100644
--- a/erpnext/setup/doctype/naming_series/naming_series.py
+++ b/erpnext/setup/doctype/naming_series/naming_series.py
@@ -173,4 +173,6 @@
 def get_default_naming_series(doctype):
 	naming_series = frappe.get_meta(doctype).get_field("naming_series").options or ""
 	naming_series = naming_series.split("\n")
-	return naming_series[0] or naming_series[1]
+	out = naming_series[0] or (naming_series[1] if len(naming_series) > 1 else None)
+	if out:
+		frappe.throw(_("Please set Naming Series for {0} via Setup > Settings > Naming Series").format(doctype))
diff --git a/erpnext/support/doctype/issue/issue.py b/erpnext/support/doctype/issue/issue.py
index 51322e6..2555bfa 100644
--- a/erpnext/support/doctype/issue/issue.py
+++ b/erpnext/support/doctype/issue/issue.py
@@ -37,7 +37,6 @@
 				if values:
 					self.contact, self.customer = values
 
-
 			if not self.company:
 				self.company = frappe.db.get_value("Lead", self.lead, "company") or \
 					frappe.db.get_default("company")