patch to set default value as 1
diff --git a/erpnext/accounts/doctype/accounts_settings/accounts_settings.json b/erpnext/accounts/doctype/accounts_settings/accounts_settings.json
index 3598052..c389b5c 100644
--- a/erpnext/accounts/doctype/accounts_settings/accounts_settings.json
+++ b/erpnext/accounts/doctype/accounts_settings/accounts_settings.json
@@ -201,6 +201,7 @@
    "bold": 0, 
    "collapsible": 0, 
    "columns": 0, 
+   "default": "1", 
    "fieldname": "unlink_payment_on_cancellation_of_invoice", 
    "fieldtype": "Check", 
    "hidden": 0, 
@@ -234,7 +235,7 @@
  "issingle": 1, 
  "istable": 0, 
  "max_attachments": 0, 
- "modified": "2016-10-19 16:37:11.664552", 
+ "modified": "2016-10-20 16:12:38.595075", 
  "modified_by": "Administrator", 
  "module": "Accounts", 
  "name": "Accounts Settings", 
diff --git a/erpnext/patches.txt b/erpnext/patches.txt
index 84312b8..7d599d7 100644
--- a/erpnext/patches.txt
+++ b/erpnext/patches.txt
@@ -339,4 +339,5 @@
 erpnext.patches.v7_0.update_status_of_zero_amount_sales_order
 erpnext.patches.v7_1.add_field_for_task_dependent
 erpnext.patches.v7_0.repost_bin_qty_and_item_projected_qty
-erpnext.patches.v7_1.set_prefered_contact_email
\ No newline at end of file
+erpnext.patches.v7_1.set_prefered_contact_email
+execute:frappe.db.sql("update `tabSingles` set value = 1 where field = 'unlink_payment_on_cancellation_of_invoice' and doctype = 'Accounts Settings'")
\ No newline at end of file