No collation was set by the server for the current connection in TediousJS

I'm using the newBulkLoad method of the Connection class of TediousJS.

After trying to execute this piece of code:

bulkLoad.addRow(TYPES.Null, col2, col3, col4, col5, TYPES.Null, col7, 
                                col8, col9, TYPES.Null, TYPES.Null, TYPES.Null);

I'm receiving the following error on that line:

No collation was set by the server for the current connection

I've previously setup the columns as specified in the URL above. What does this error mean? How can I solve it?