Unable to update a field internal name. Erro “Property or indexer 'Field.InternalName' cannot be assigned to — it is read only”

Question

I have the following CSOM code to update a field internal name:-

using (ClientContext context = new ClientContext("https://*****.sharepoint.com/sites/Intranet/"))
            {
                try
                {
                    context.Credentials = new SharePointOnlineCredentials("***@***.onmicrosoft.com", passWord);
                    var a =  context.Site.RootWeb.Fields.GetByInternalNameOrTitle("Confidentiality_x0009_");
                    a.InternalName = "Confidentiality";
                    a.Update();
                    a.UpdateAndPushChanges(true);

but i am getting this error:-

Suppression State
Error   CS0200  Property or indexer 'Field.InternalName' cannot be assigned to -- it is read only

Answer 1

You cannot change the internal name of a field once created. That is by design. You will have to delete and recreate the field.

Answer 2

Just like Akshay said, once the column is created the internal name is set and cannot be changed later. If you really need to have another internal name, you will need to delete the column and recreate it with a name your desire.