https://community.blueprism.com/t5/Product-Forum/Using-c-in-Code-block/m-p/49486#M4886 I tried using c# in code block. It was working fine when i tried assigning simple string variables. But when i try to create a Collection or a datatable and assign it to a variable I'm getting few errors such as System.ComponentModel.MarshalByValueComponent is in a assembly that is not referenced. System.ComponentModel.IListSource is in a assembly that is not referenced. System.ComponentModel.ISupportIniatializeNotification is in a assembly that is not referenced. Code Block DataTable table = new DataTable(); table.Columns.Add("Dosage", typeof(int)); table.Columns.Add("Drug", typeof(string)); table.Columns.Add("Patient", typeof(string)); table.Columns.Add("Date", typeof(DateTime)); table.Rows.Add(25, "Indocin", "David", DateTime.Now); table.Rows.Add(50, "Enebrel", "Sam", DateTime.Now); table.Rows.Add(10, "Hydralazine", "Christoff", DateTime.Now); table.Rows.Add(21, "Combivent", "Janet", DateTime.Now); table.Rows.Add(100, "Dilantin", "Melanie", DateTime.Now); Output = table; Thu, 01 Dec 2016 21:48:00 GMT vignesh_sundar 2016-12-01T21:48:00Z https://community.blueprism.com/t5/Product-Forum/Using-c-in-Code-block/m-p/49486#M4886 I tried using c# in code block. It was working fine when i tried assigning simple string variables. But when i try to create a Collection or a datatable and assign it to a variable I'm getting few errors such as System.ComponentModel.MarshalByValueComponent is in a assembly that is not referenced. System.ComponentModel.IListSource is in a assembly that is not referenced. System.ComponentModel.ISupportIniatializeNotification is in a assembly that is not referenced. Code Block DataTable table = new DataTable(); table.Columns.Add("Dosage", typeof(int)); table.Columns.Add("Drug", typeof(string)); table.Columns.Add("Patient", typeof(string)); table.Columns.Add("Date", typeof(DateTime)); table.Rows.Add(25, "Indocin", "David", DateTime.Now); table.Rows.Add(50, "Enebrel", "Sam", DateTime.Now); table.Rows.Add(10, "Hydralazine", "Christoff", DateTime.Now); table.Rows.Add(21, "Combivent", "Janet", DateTime.Now); table.Rows.Add(100, "Dilantin", "Melanie", DateTime.Now); Output = table; Thu, 01 Dec 2016 21:48:00 GMT https://community.blueprism.com/t5/Product-Forum/Using-c-in-Code-block/m-p/49486#M4886 vignesh_sundar 2016-12-01T21:48:00Z https://community.blueprism.com/t5/Product-Forum/Using-c-in-Code-block/m-p/49487#M4887 You need to Add External Reference to the appropiate .NET dll, in your case is System.dll Fri, 02 Dec 2016 01:07:00 GMT https://community.blueprism.com/t5/Product-Forum/Using-c-in-Code-block/m-p/49487#M4887 AlainBismark 2016-12-02T01:07:00Z https://community.blueprism.com/t5/Product-Forum/Using-c-in-Code-block/m-p/49488#M4888 In this case if i add an external reference to mscorlib.dll, I'm getting a new error ""An assembly with the same identity exists. Try removing the duplicate reference"". Fri, 02 Dec 2016 11:14:00 GMT https://community.blueprism.com/t5/Product-Forum/Using-c-in-Code-block/m-p/49488#M4888 vignesh_sundar 2016-12-02T11:14:00Z