Error:
Odoo Server Error

Traceback (most recent call last):
  File "/opt/odoo/odoo/addons/base/models/ir_http.py", line 237, in _dispatch
    result = request.dispatch()
  File "/opt/odoo/odoo/http.py", line 683, in dispatch
    result = self._call_function(**self.params)
  File "/opt/odoo/odoo/http.py", line 359, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/opt/odoo/odoo/service/model.py", line 94, in wrapper
    return f(dbname, *args, **kwargs)
  File "/opt/odoo/odoo/http.py", line 347, in checked_call
    result = self.endpoint(*a, **kw)
  File "/opt/odoo/odoo/http.py", line 912, in __call__
    return self.method(*args, **kw)
  File "/opt/odoo/odoo/http.py", line 531, in response_wrap
    response = f(*args, **kw)
  File "/opt/odoo/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/odoo/http.py", line 531, in response_wrap
    response = f(*args, **kw)
  File "/opt/odoo/addons/web/controllers/main.py", line 1389, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/opt/odoo/addons/web/controllers/main.py", line 1381, in _call_kw
    return call_kw(request.env[model], method, args, kwargs)
  File "/opt/odoo/odoo/api.py", line 399, in call_kw
    result = _call_kw_multi(method, model, args, kwargs)
  File "/opt/odoo/odoo/api.py", line 386, in _call_kw_multi
    result = method(recs, *args, **kwargs)
  File "/opt/odoo/odoo/models.py", line 3022, in read
    return self._read_format(fnames=fields, load=load)
  File "/opt/odoo/odoo/models.py", line 3042, in _read_format
    vals[name] = convert(record[name], record, use_name_get)
  File "/opt/odoo/odoo/models.py", line 5689, in __getitem__
    return self._fields[key].__get__(self, type(self))
  File "/opt/odoo/odoo/fields.py", line 2485, in __get__
    return super().__get__(records, owner)
  File "/opt/odoo/odoo/fields.py", line 1021, in __get__
    self.compute_value(recs)
  File "/opt/odoo/odoo/fields.py", line 1177, in compute_value
    records._compute_field_value(self)
  File "/opt/odoo/addons/mail/models/mail_thread.py", line 410, in _compute_field_value
    return super()._compute_field_value(field)
  File "/opt/odoo/odoo/models.py", line 4069, in _compute_field_value
    getattr(self, field.compute)()
  File "/opt/odoo/odoo_tvone/ins_purchase_approval/models/purchase_order.py", line 114, in _compute_selected_approvers
    if group and group.amount_limit >= self.estimated_cost:
Exception

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

Traceback (most recent call last):
  File "/opt/odoo/odoo/http.py", line 639, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/opt/odoo/odoo/http.py", line 315, in _handle_exception
    raise exception.with_traceback(None) from new_cause
AttributeError: 'purchase.order' object has no attribute 'estimated_cost'