Error while opening erpnext

Hi there,
I am trying to open the site i have created and unable to open it.
Earlier it used to, but i tried to create a new site so that i can have two instance for the same. But now when i am trying to open the older site i am unable to do so.
It displays the following error.

Traceback (most recent call last):
File “/home/user/frappe-bench/apps/frappe/frappe/website/”, line 32, in render
data = render_page_by_language(path)
File “/home/user/frappe-bench/apps/frappe/frappe/website/”, line 101, in render_page_by_language
return render_page(path)
File “/home/user/frappe-bench/apps/frappe/frappe/website/”, line 117, in render_page
return build(path)
File “/home/user/frappe-bench/apps/frappe/frappe/website/”, line 124, in build
return build_page(path)
File “/home/user/frappe-bench/apps/frappe/frappe/website/”, line 137, in build_page
context = get_context(path)
File “/home/user/frappe-bench/apps/frappe/frappe/website/”, line 18, in get_context
context = build_context(context)
File “/home/user/frappe-bench/apps/frappe/frappe/website/”, line 84, in build_context
update_controller_context(context, context.controller)
File “/home/user/frappe-bench/apps/frappe/frappe/website/”, line 46, in update_controller_context
ret = module.get_context(context)
File “/home/user/frappe-bench/apps/frappe/frappe/www/”, line 21, in get_context
boot = frappe.sessions.get()
File “/home/user/frappe-bench/apps/frappe/frappe/”, line 118, in get
bootinfo[“notification_info”] = get_notification_info_for_boot()
File “/home/user/frappe-bench/apps/frappe/frappe/desk/”, line 133, in get_notification_info_for_boot
out = get_notifications()
File “/home/user/frappe-bench/apps/frappe/frappe/desk/”, line 26, in get_notifications
“open_count_doctype”: get_notifications_for_doctypes(config, notification_count),
File “/home/user/frappe-bench/apps/frappe/frappe/desk/”, line 92, in get_notifications_for_doctypes
filters=condition, limit_page_length = 21, as_list=True, ignore_ifnull=True))
File “/home/user/frappe-bench/apps/frappe/frappe/”, line 1069, in get_list
return frappe.model.db_query.DatabaseQuery(doctype).execute(None, *args, **kwargs)
File “/home/user/frappe-bench/apps/frappe/frappe/model/”, line 80, in execute
result = self.build_and_run()
File “/home/user/frappe-bench/apps/frappe/frappe/model/”, 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/user/frappe-bench/apps/frappe/frappe/”, line 148, in sql
File “/home/user/frappe-bench/env/local/lib/python2.7/site-packages/MySQLdb/”, line 205, in execute
self.errorhandler(self, exc, value)
File “/home/user/frappe-bench/env/local/lib/python2.7/site-packages/MySQLdb/”, line 36, in defaulterrorhandler
raise errorclass, errorvalue
OperationalError: (1054, “Unknown column ‘tabTraining.training_status’ in ‘where clause’”)

Did you create a custom Doctype named Training ?

Actually i have created a new site and installed the same erpnext app in the new site.
I want to have multiple instance so that in one i can make changes and then migrate it to the new one.

@Ujjawal Just check any custom code you have written for Training doctype there seems to be a syntax error in the code. Check if you have used ‘training_status’ anywhere in the code and if the field exists in the doctype.

I have used it and also i have made it comment and tried but still no luck.
How can i create a new Instance the older site