Mount Error on macOS

You cannot mount drive on macOS with a message box like below one if there are many virtual devices on your Mac (like VMWare, Virtual Box, Intel HAXM, TunTap, etc.)


It is a known problem only with macOS.

From following page:

"FUSE needs to register a virtual device for exchanging messages between the kernel and the actual file system implementation running in user space. The number of available device slots is limited by macOS. So if you are using other software like VMware, VirtualBox, TunTap, Intel HAXM, …, that eat up all free device slots, FUSE will not be able to register its virtual device.

On a brand new install of macOS 10.12 there are six free device slots. VMware and VirtualBox require multiple slots each. TunTap (VPN) requires two slots, as far as I know. Intel HAXM requires at least one slot."

You can list current virtual devices using kextstat | grep -v apple.

You can unload virtual device with kextunload but it’s a temporary solution because the virtual device will be allocated again on next reboot. Consider uninstall some applications which uses virtual devices.