Same problem using Firefox 57.0.2 (64-bit). On my laptop the language selection box doesn't work, on my desktop, it works. Same extensions 
But you can force the language selection list to appear: click on the language field and press ALT+Down keys
After you get inside the management console another odd behaviour: the mouse button doesn't work on buttons or items on the left pane (System, Storage, Settings...) but works to slide the scrollers and slider buttons o_O
Did that and bobafettathotmail already updated folder2ram! 
I just installed OMV 3.0 and I playing with it. So far, very impressed! A lot of what I already have on my small server but easily configurable and customisable
My system drive is a USB pendrive inside the box, so thanks also for the flash memory plugin
Looking the logs I found that warning;
Oct 12 22:45:43 ubuntu systemd[1]: Configuration file /lib/systemd/system/folder2ram_startup.service is marked world-writable. Please remove world writability permission bits. Proceeding anyway.
Oct 12 22:45:43 ubuntu systemd[1]: Configuration file /lib/systemd/system/folder2ram_shutdown.service is marked world-writable. Please remove world writability permission bits. Proceeding anyway.
Is it ok to fix the permission or are they needed due to permissions problems during bootup/shutdown?
