Are you using the Fluenz Online via browser (if so, which browser?) or the desktop version? And what is the OS version of your Mac? You can email us directly to troubleshoot further at firstname.lastname@example.org
I bumbled my way into installing one. One problem is that the format is markedly different from previous ones like my Italian program and to me it does not seem very intuitive. Instead it is "tryandfindtheansweritive" For example, I still haven't figured out how to use the Accents window. So I just click on "Answer" and highlight and paste the word with the accent marked.