CRM 2016 Online: Need help retrieving POAA records using OdataQuery in webresource

CRM 2016 Online: Need help retrieving POAA records using OdataQuery in webresource.

We have a scenario where we need to query/access 'PrincipalObjectAttributeAccess' table from Webresource. Can any one help to access /retrieving data form POAA.

I am getting error message:"{\r\n\"error\": {\r\n\"code\": \"\", \"message\": {\r\n\"lang\": \"en-US\", \"value\": \"Operator 'eq' incompatible with operand types 'Microsoft.Crm.Metadata.ComplexTypeInstance`1[[Microsoft.Xrm.Sdk.EntityReference, Microsoft.Xrm.Sdk, Version=8.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]' and 'System.Guid' at position 78.\"\r\n}\r\n}\r\n}" when it is loaded on the form.

Below is the value passed to the system during the run time

function FindLicenseduser()
{

    var ServerUrl = Xrm.Page.context.getClientUrl();
    var UserId = Xrm.Page.context.getUserId();
    var OpptyId = Xrm.Page.data.entity.getId();
    var ODataPath = ServerUrl + "/XRMServices/2011/OrganizationData.svc/";
    // AttributeID - CF9E1FA3-2EFF-4B9A-8850-87197AE7DE98
    var AttributeId = "{CF9E1FA3-2EFF-4B9A-8850-87197AE7DE98}";
    var OdataQuery = "PrincipalObjectAttributeAccessSet?$select=ReadAccess, PrincipalId,PrincipalObjectAttributeAccessId&$filter=AttributeId eq (guid'" + AttributeId + "') and PrincipalId eq (guid'" + UserId + "') and ObjectId eq (guid'" + OpptyId + "')";
    ODataPath = ODataPath + OdataQuery;
    var retrieveUserReq = new XMLHttpRequest();
    retrieveUserReq.open("GET", ODataPath, true);

    retrieveUserReq.setRequestHeader("Accept", "application/json");
    retrieveUserReq.setRequestHeader("Content-Type", "application/json; charset=utf-8");
    retrieveUserReq.onreadystatechange = function () {
        retrieveUserReqCallBack(this);
    };
    retrieveUserReq.send();

}

function retrieveUserReqCallBack(retrieveUserReq)
{
    if (retrieveUserReq.readyState == 4 /* complete */) {

        if (retrieveUserReq.status == 200) {
            var retrievedUserId = this.parent.JSON.parse(retrieveUserReq.responseText).d;

            alert(retrievedUserId.PrincipalId);

        }

        else {
            showMessage("retrieveAccountReqCallBack function failure END");
        }
    }
}

Madhu M.