Error while saving a 'Read Only' Field


I am following the frappe developer tutorial. I created Article, Library Member Doctype. While creating Library Membership DocType, I get this error.

Membership First Name field is ‘Read Only’ Filed Type linked to Library Member. I am not able to save it.

I use the lastest version of Erpnext.

Traceback (most recent call last): File "/home/frappe/frappe-bench/apps/frappe/frappe/", line 55, in application response = frappe.handler.handle() File "/home/frappe/frappe-bench/apps/frappe/frappe/", line 19, in handle execute_cmd(cmd) File "/home/frappe/frappe-bench/apps/frappe/frappe/", line 40, in execute_cmd ret =, **frappe.form_dict) File "/home/frappe/frappe-bench/apps/frappe/frappe/", line 897, in call return fn(*args, **newargs) File "/home/frappe/frappe-bench/apps/frappe/frappe/desk/form/", line 22, in savedocs File "/home/frappe/frappe-bench/apps/frappe/frappe/model/", line 223, in save return self._save(*args, **kwargs) File "/home/frappe/frappe-bench/apps/frappe/frappe/model/", line 252, in _save self.run_before_save_methods() File "/home/frappe/frappe-bench/apps/frappe/frappe/model/", line 750, in run_before_save_methods self.run_method("validate") File "/home/frappe/frappe-bench/apps/frappe/frappe/model/", line 651, in run_method out = Document.hook(fn)(self, *args, **kwargs) File "/home/frappe/frappe-bench/apps/frappe/frappe/model/", line 858, in composer return composed(self, method, *args, **kwargs) File "/home/frappe/frappe-bench/apps/frappe/frappe/model/", line 841, in runner add_to_return_value(self, fn(self, *args, **kwargs)) File "/home/frappe/frappe-bench/apps/frappe/frappe/model/", line 645, in fn = lambda self, *args, **kwargs: getattr(self, method)(*args, **kwargs) File "/home/frappe/frappe-bench/apps/frappe/frappe/core/doctype/doctype/", line 62, in validate self.update_fields_to_fetch() File "/home/frappe/frappe-bench/apps/frappe/frappe/core/doctype/doctype/", line 100, in update_fields_to_fetch link_fieldname = link_fieldname File "/home/frappe/frappe-bench/apps/frappe/frappe/", line 148, in sql self._cursor.execute(query) File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/MySQLdb/", line 205, in execute self.errorhandler(self, exc, value) File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/MySQLdb/", line 36, in defaulterrorhandler raise errorclass, errorvalue OperationalError: (1054, "Unknown column 'target.member_first_name' in 'field list'")


Error message indicates that field name mentioned as Option for the Read Only field is not correct. Please check Field Name in the source document, and update accordingly in the Target Field which is Read Only.