Some of my clients have had problems efiling the FBAR on the BSA system. The FINCEN support group have confirmed that the system works only using Internet Explorer. So if you need to file an FBAR, use Internet Explorer, not Firefox or Chrome (or any other browser).
As a reminder, if you need to file an FBAR you have until Saturday, June 30th to file the form. Note that is a receipt deadline, so if you’re putting it in the mail do it now, not later.