By far the most common cause is failure to deal with NULL values in the results. Adding code to check and resolve NULL results cleaned up a lot of these problems. You may want to add some explicit NULL tests for the Parameter column.

The second most common problem was code that “assumed” columns with “number” in the name only contained numeric data and tried to assign the column values to a numeric variable.

Last, if the Parameter column is defined as something larger than VARCHAR(2000) (e.g., VARCHAR(MAX), TEXT, etc.), then you may need to rewrite the VB code to deal with the data in “chunks”. Assuming you are using SQL Server, open the Books Online and search for “chunk”. There is plenty of material on how to handle large text columns.

As for the error, is there something different in this problematic field’s data ? Maybe special characters ?