Importing data from Excel is often problematic.

One of the main reasons is that by default the datatype of each column is based on the data in the first 8 rows only so if you have a column of mixed numeric and character if the first 8 rows are numeric then the whole of the column will be treated as numeric and character values may cause a failure or be represented as null.

Is your Data Flow Task failing when it is reading from the Excel file or is if failing somewhere else? If the Excel source component turns red then it is failing when reading from Excel.

Jez