TransactionSource Field Possible Values in Odata Query

Hi,

I got error when trying to query data from ProjectTransactionsHandling.svc. One of the parameter I want to filter is TransactionSource. However, I got below error:

{
    "error": {
        "code": "ODATA_PROVIDER_ERROR",
        "message": "An internal server error occurred. Contact administrator.",
        "details": [
            {
                "code": "TYPES_NOT_COMPATIBLE",
                "message": "The types 'IfsApp.ProjectTransactionsHandling.TransactionSource' and 'Edm.String' are not compatible."
            }
        ]
    }
}

Please advise how to get pass this.

IFS APP10 UPD19

Regards

Hami