Linq The specified type 'string' is not a valid provider type.
- by Joe Pitz
Using Linq to call a stored procedure that passes a single string,  The stored procedure returns a data set row that contains a string and an int.
Code:
 PESQLDataContext pe = new PESQLDataContext(strConnStr);
        pe.ObjectTrackingEnabled = false;
 gvUnitsPassed.DataSource = pe.PassedInspection(Line);
 gvUnitsPassed.DataBind();
pe.dispose();
When the code runs an exception gets called below:
The exception is thrown at the IExecuteResult result = statement:
Enclosed is my result class in the designer.cs file.
[Function(Name = "dbo.PassedInspection")]
    public ISingleResult<PassedInspectionResult> PassedInspection([Parameter(Name = "Model", DbType = "VarChar(4)")] string model)
    {
        IExecuteResult result = this.ExecuteMethodCall(this, ((MethodInfo)(MethodInfo.GetCurrentMethod())), model);
        return ((ISingleResult<PassedInspectionResult>)(result.ReturnValue));
    }
    public partial class PassedInspectionResult
    {
        private string _Date;
        private int _Passed;
        public PassedInspectionResult()
        {
        }
        [Column(Storage = "_Date", DbType = "string NULL")]
        public string Date
        {
            get
            {
                return this._Date;
            }
            set
            {
                if ((this._Date != value))
                {
                    this._Date = value;
                }
            }
        }
        [Column(Storage = "_Passed", DbType = "Int NULL")]
        public int Passed
        {
            get
            {
                return this._Passed;
            }
            set
            {
                if ((this._Passed != value))
                {
                    this._Passed = value;
                }
            }
        }
    }
}
I have other stored procedures with similar arguments that run just fine.
Thanks