You can never preview reports in the Report Center. It always shows some sequence of letters and numbers and you have to click the Open button, let it download, and open in order to view. The Preview button should open in the browser, if I understand correctly. (Screenshot is attached)

Also, Send to Email button in the Report Center always send Accrual basis reports, no matter if you customize it the cash basis. They also always send calendar year reports, even if you customize it to a different date range, such as a fiscal year.

I've had to send fiscal year financial reports over three times to a client, at a critical deadline, and they turned out to be calendar year.