Sorry, no ideas 
Have you installed bluez system library etc.? Perhaps this points to right direction.
Also, docs say that
Also note that the OS user needs to be a member of the “bluetooth” group of Linux in order to have the rights to access the BlueZ stack.
Make sure you have bluez version below 5.48. As docs say
Please note that at least BlueZ 5.43 is required, while 5.48 or above are not (yet) supported either.