minor fix
diff --git a/erpnext/setup/utils.py b/erpnext/setup/utils.py
index f003ce4..49c439b 100644
--- a/erpnext/setup/utils.py
+++ b/erpnext/setup/utils.py
@@ -120,8 +120,9 @@
 		_role.save()
 
 	# add all roles to users
-	user = frappe.get_doc("User", "Administrator")
-	user.add_roles(*[role.get("name") for role in roles])
+	if roles:
+		user = frappe.get_doc("User", "Administrator")
+		user.add_roles(*[role.get("name") for role in roles])
 
 	domains = frappe.get_list("Domain")
 	if not domains: