I query a children dataset with parent id (master-detail datatype) as one of the columns using API 8.0. When I try to update the dataset, it gives error as the following:

{errors:{fields:Name,Opportunity__c, message:"Unable to create/update fields: Name, Opportunity__c. Please check the security settings of this field and verify that it is read/write for your profile.', statusCode:'INVALID_FIELD_FOR_INSERT_UPDATE',},id:null,success:'false',}

but it was working when I use API 7.0. Any clue anyone? Thanks