I am also getting same issue while saving/opening opportunity.
ERPNext : v7.1.5
Frappe Framework: v7.1.4
Traceback (most recent call last): File "/home/ubuntu/frappe-bench/apps/frappe/frappe/app.py", line 55, in application response = frappe.handler.handle() File "/home/ubuntu/frappe-bench/apps/frappe/frappe/handler.py", line 19, in handle execute_cmd(cmd) File "/home/ubuntu/frappe-bench/apps/frappe/frappe/handler.py", line 36, in execute_cmd ret = frappe.call(method, **frappe.form_dict) File "/home/ubuntu/frappe-bench/apps/frappe/frappe/__init__.py", line 890, in call return fn(*args, **newargs) File "/home/ubuntu/frappe-bench/apps/frappe/frappe/desk/notifications.py", line 204, in get_open_count filters=filters, limit=6, distinct=True, ignore_ifnull=True)) File "/home/ubuntu/frappe-bench/apps/frappe/frappe/__init__.py", line 1096, in get_all return get_list(doctype, *args, **kwargs) File "/home/ubuntu/frappe-bench/apps/frappe/frappe/__init__.py", line 1069, in get_list return frappe.model.db_query.DatabaseQuery(doctype).execute(None, *args, **kwargs) File "/home/ubuntu/frappe-bench/apps/frappe/frappe/model/db_query.py", line 80, in execute result = self.build_and_run() File "/home/ubuntu/frappe-bench/apps/frappe/frappe/model/db_query.py", line 104, in build_and_run return frappe.db.sql(query, as_dict=not self.as_list, debug=self.debug, update=self.update) File "/home/ubuntu/frappe-bench/apps/frappe/frappe/database.py", line 148, in sql self._cursor.execute(query) File "/home/ubuntu/frappe-bench/env/local/lib/python2.7/site-packages/MySQLdb/cursors.py", line 205, in execute self.errorhandler(self, exc, value) File "/home/ubuntu/frappe-bench/env/local/lib/python2.7/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler raise errorclass, errorvalue OperationalError: (1054, "Unknown column 'tabSupplier Quotation.prevdoc_docname' in 'where clause'")