Dixon,
I've been doing Crystal for many years and the only Excel sheets that can be used are .xls not the newer .xlsx.
To use one as input, have very simple headings on the columns in row 1. Then in CRW, go to the Database Expert and click on 'Create New Connection'. Click on 'Access/Excel (DAO)'. When the 'Access/Excel (DAO)' screen appears, browse to the .xls file to select it. Then change the database type to Excel 8. Click Finish. You should now see the Excel file under 'My Connections'. It works like any other file where you can link to it etc..
I'm hoping in 2016 version .xlsx files can be used.
HTH,
Diana