Facing Error of "Against Doctype must be set first" for generating quotation from a custom doctype Costing

Traceback (most recent call last):
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/app.py”, line 64, in application
19:33:19 web.1 | response = frappe.api.handle()
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/api.py”, line 59, in handle
19:33:19 web.1 | return frappe.handler.handle()
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/handler.py”, line 24, in handle
19:33:19 web.1 | data = execute_cmd(cmd)
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/handler.py”, line 64, in execute_cmd
19:33:19 web.1 | return frappe.call(method, **frappe.form_dict)
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/init.py”, line 1064, in call
19:33:19 web.1 | return fn(*args, **newargs)
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/desk/form/save.py”, line 21, in savedocs
19:33:19 web.1 | doc.save()
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/model/document.py”, line 273, in save
19:33:19 web.1 | return self._save(*args, **kwargs)
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/model/document.py”, line 296, in _save
19:33:19 web.1 | self.insert()
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/model/document.py”, line 224, in insert
19:33:19 web.1 | self._validate_links()
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/model/document.py”, line 759, in validate_links
19:33:19 web.1 | result = d.get_invalid_links(is_submittable=self.meta.is_submittable)
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/model/base_document.py”, line 461, in get_invalid_links
19:33:19 web.1 | frappe.throw(
(“{0} must be set first”).format(self.meta.get_label(df.options)))
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/init.py”, line 377, in throw
19:33:19 web.1 | msgprint(msg, raise_exception=exc, title=title, indicator=‘red’, is_minimizable=is_minimizable)
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/init.py”, line 356, in msgprint
19:33:19 web.1 | _raise_exception()
19:33:19 web.1 | File “/home/tallal/frappe-bench/apps/frappe/frappe/init.py”, line 316, in _raise_exception
19:33:19 web.1 | raise raise_exception(msg)
19:33:19 web.1 | frappe.exceptions.ValidationError: Against Doctype must be set first