This error most likely means that the table a datapage is trying to insert into is different that the table already created in the database. To resolve the issue you delete the table in the database using SQL Server Management Studio or, if you want to keep the data, you can modify the table or dataset's field properties or rename the table and merge the data from both tables later. Also, beware of writing to the same table with different datasets, this can cause the truncation error to reoccur.