I have a mac mini, when testing using both stable and dev channels,
i can mount an ISO as expected, but then when you say Unmount,
it says it unmounted successfully but in fact it doesnt actually unmount its still mounted on the mac
i ran a custom build on my jetkvm and console is showing the error
Remove Mass Storage Image Error failed to set image path: write /sys/kernel/config/usb_gadget/jetkvm/functions/mass_storage.usb0/lun.0/file: device or resource busy
also side note: when you mount an iso it doesnt actually close the window, it stays open, thats a GUI bug i think