Merge pull request #71 from Alchez/fix-chart-of-accounts-tree

erpnext/accounts/doctype/chart_of_accounts_importer/chart_of_accounts_importer.py

@@ -226,7 +226,7 @@ def return_parent(data, child):
 							"The parent account {0} does not exists in the uploaded template"
 						).format(frappe.bold(parent_account))
 					)
-				return [child] + parent_account_list
+				return [child] + (parent_account_list or [])
 
 	charts_map = defaultdict(dict)
 	paths = []