customer field in Subscriber should be Link
diff --git a/erpnext/accounts/doctype/subscriber/subscriber.json b/erpnext/accounts/doctype/subscriber/subscriber.json
index 39a23b1..28a57d8 100644
--- a/erpnext/accounts/doctype/subscriber/subscriber.json
+++ b/erpnext/accounts/doctype/subscriber/subscriber.json
@@ -51,7 +51,7 @@
    "collapsible": 0, 
    "columns": 0, 
    "fieldname": "customer", 
-   "fieldtype": "Select", 
+   "fieldtype": "Link", 
    "hidden": 0, 
    "ignore_user_permissions": 0, 
    "ignore_xss_filter": 0, 
@@ -87,7 +87,7 @@
  "issingle": 0, 
  "istable": 0, 
  "max_attachments": 0, 
- "modified": "2018-02-24 11:17:46.809140", 
+ "modified": "2018-02-26 04:40:16.510290", 
  "modified_by": "Administrator", 
  "module": "Accounts", 
  "name": "Subscriber",