As of current release , we don't support reading excel files from Amazon S3 or S3 V2 connector.We may need to use pre-processing script to covert the XLS format to CSV and read .
The Microsoft Excel file must be located on the same machine on which the Secure Agent runs. So it is not possible to get excel file from S3. And the connector is currently in maintenance mode.
For S3 connector, if the file is an excel file (extension .xls) then it will not be able to read as it can read text files (.txt, .csv). For more details, check these two links;
For a workaround, I can suggest converting excel file into CSV file and process. That would resolve this issue.