Error:
Odoo Server Error

Traceback (most recent call last):
  File "/opt/odoo/odoo14-normal/odoo/odoo/addons/base/models/ir_http.py", line 237, in _dispatch
    result = request.dispatch()
  File "/opt/odoo/odoo14-normal/odoo/odoo/http.py", line 685, in dispatch
    result = self._call_function(**self.params)
  File "/opt/odoo/odoo14-normal/odoo/odoo/http.py", line 361, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/opt/odoo/odoo14-normal/odoo/odoo/service/model.py", line 94, in wrapper
    return f(dbname, *args, **kwargs)
  File "/opt/odoo/odoo14-normal/odoo/odoo/http.py", line 349, in checked_call
    result = self.endpoint(*a, **kw)
  File "/opt/odoo/odoo14-normal/odoo/odoo/http.py", line 914, in __call__
    return self.method(*args, **kw)
  File "/opt/odoo/odoo14-normal/odoo/odoo/http.py", line 533, in response_wrap
    response = f(*args, **kw)
  File "/opt/odoo/odoo14-normal/odoo_tvone/ks_list_view_manager/controllers/lvm_controller.py", line 16, in call_kw
    call_kw_result = super(LvmController, self).call_kw(model, method, args, kwargs, path)
  File "/opt/odoo/odoo14-normal/odoo/odoo/http.py", line 533, in response_wrap
    response = f(*args, **kw)
  File "/opt/odoo/odoo14-normal/odoo/addons/web/controllers/main.py", line 1394, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/opt/odoo/odoo14-normal/odoo/addons/web/controllers/main.py", line 1386, in _call_kw
    return call_kw(request.env[model], method, args, kwargs)
  File "/opt/odoo/odoo14-normal/odoo/odoo/api.py", line 399, in call_kw
    result = _call_kw_multi(method, model, args, kwargs)
  File "/opt/odoo/odoo14-normal/odoo/odoo/api.py", line 386, in _call_kw_multi
    result = method(recs, *args, **kwargs)
  File "/opt/odoo/odoo14-normal/odoo/odoo/models.py", line 6264, in onchange
    record._onchange_eval(name, field_onchange[name], result)
  File "/opt/odoo/odoo14-normal/odoo/odoo/models.py", line 6006, in _onchange_eval
    method_res = method(self)
  File "/opt/odoo/odoo14-normal/odoo_tvone/budget_control/models/budget_allocation.py", line 174, in _onchange_general_budget_id
    self.budget_line_id = self.env['crossovered.budget.lines'].search([('general_budget_id','=',self.general_budget_id.id),('analytic_account_id','=',self.analytic_account_id.id)]).id
  File "/opt/odoo/odoo14-normal/odoo/odoo/fields.py", line 3816, in __get__
    raise ValueError("Expected singleton: %s" % record)
Exception

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/opt/odoo/odoo14-normal/odoo/odoo/http.py", line 641, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/opt/odoo/odoo14-normal/odoo/odoo/http.py", line 317, in _handle_exception
    raise exception.with_traceback(None) from new_cause
ValueError: Expected singleton: crossovered.budget.lines(227, 231, 374, 380, 384, 385, 389, 443, 447)