Webtrends Analytics 9 Adminstration Guide, November 2012
The data file must be a flat file that meets certain requirements.
The file must contain only the data. Do not include column headings, notes, extra carriage returns, or any other characters that are not part of the data you want to import.
The order of the columns in the data file must match the order of the columns in your lookup table. If the order of columns does not match, the import fails and produces column errors. If the column types match but the columns are not in the correct order, the data imports successfully, but its meaning is lost because the wrong data is associated with the wrong column heading.
The flat file must not be tab-delimited.