Error: The “Derived Column” failed because truncation occurred, and the truncation row disposition on “Derived Column.Outputs[Derived Column Output].Columns[FilePath]” specifies failure on truncation. A truncation error occurred on the specified object of the specified component.

We might get the error while using Derived Column in our SSIS Package

To fix it right click the Derived Column component and select Show Advanced Editor ..

Go to Input and Output Properties tab, expand Derived Column Output and select the field and update the length in the properties window.

Hope this helps..