销售订单选择完客户后报错

销售订单选择完客户后报错，提示“表达式计算出错:FReceiveId = FCustId”

详细信息如下：

发生时间： 12:05:49
错误编号： PyExpressionEvaluator
错误信息： 表达式计算出错:FReceiveId = FCustId
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调用堆栈：
在 Kingdee.BOS.Scripting.PyExpressionEvaluator.Run(Expression expression, ExpressionContext context)
在 Kingdee.BOS.Business.DynamicForm.BusinessService.Calculate.DoAction(FormBusinessServiceArgs e)
在 Kingdee.BOS.Core.DynamicForm.FormBusinessServiceUtil.DoAction(IDynamicFormView view, FormBusinessServiceArgs e)
在 Kingdee.BOS.Core.DynamicForm.FormBusinessServiceUtil.InvokeServices(IDynamicFormView view, Object source, IEnumerable`1 services, Int32 actionType, String activeEntity, DynamicObject activeRow, Int32 rowIndex)
在 Kingdee.BOS.Web.DynamicForm.BusinessServiceCaller.InvokeFormBusiness(IDynamicFormView view, Object source, List`1 formBusinessServices, Int32 actionType, String entityKey, Int32 row)
在 Kingdee.BOS.Web.DynamicForm.BusinessServiceCaller.CallUpdateBusinessService(FieldAppearance fieldAppearance, Int32 row)
在 Kingdee.BOS.Web.DynamicForm.DynamicWebFormView.DoLookUpSetFieldValue(FieldAppearance ap, ILookUpField lookUpField, Int32 rowIndex, ListSelectedRow selectRow, String combinedFieldKey)
在 Kingdee.BOS.Web.DynamicForm.DynamicWebFormView.DoLookUpAfterShow(String key, Int32 row, ILookUpField lookUpField, FieldAppearance ap, FormResult result, String combinedFieldKey)
在 Kingdee.BOS.Web.DynamicForm.DynamicWebFormView.<>c__DisplayClass4d.b__4c(FormResult result)
在 Kingdee.BOS.Web.DynamicForm.DynamicWebFormView.<>c__DisplayClass36.b__34()