I recently updated my macbook Pro and now the sixty four is not connecting I went to rane website and followed all the instructions and it's still not working also had the same problem with my NS7 II. I followed all steps listed below:

Known Issue with the Sixty-Two, Sixty-Four, Sixty-Eight and the Sixty-One: Fails to connect with Serato DJ on clean systems. Work-around is to connect the device after opening Serato DJ or hot-plugging the device while Serato DJ is open.

Most of the reported Serato DJ connection issues are resolved by removing unsupported software and associated drivers from the system (written and video walk-though below). Most Serato DJ connection issues for the SL3, SL2, and SL4 can be solved just by performing steps 1,2,4 and 7. Make sure you have the latest version of Serato DJ installed.

Confirm that the OS is version 10.11.4 or higher. Apple->About This Mac->System Report->Software
Close all applications and disconnect your Rane unit.
Run the uninstall-all script available here. This will uninstall ALL Rane device drivers.
Click the link above to download the "Uninstall-All.command" script.
Click on the Downloads folder located on the dock, select “Open in Finder” to open the folder.
While holding the control key down, click on the "Uninstall-All.command" file to open the context menu.
Select Open from the context menu.
A window will pop up with: "Uninstall-All.command" is from an unidentified developer. Are you sure you want to open it?....Click on Open.
A terminal window opens, waiting for your account password. Enter your password and hit the return key (nothing will be displayed while you are typing your password).
The script runs until [Process Completed] is shown in the terminal window.
Close the terminal window (red X).
Quit the Terminal app (Cmd-Q).
Remove the Serato Scratch Live kernel extension.
Open a Finder window.
Click on your Macintosh HD drive.
Click on the System folder.
Click on the Library folder.
Click on the Extensions folder.
Move the SeratoScratchDriver.kext file to your desktop, trash, or into a folder somewhere for safe keeping.
Remove any old outdated MIDI files.
Open a Finder window.
Click on your Macintosh HD drive.
Click on the Library folder.
Click on the Audio folder.
Open the MIDI Drivers folder.
Move old drivers to your desktop or into a folder somewhere for safe keeping.
Restart the computer.
Install the Rane El Capitan device driver for your device with the device disconnected from the computer and all applications closed. Restart the computer when prompted by the installer.
Confirm that the correct version of the driver for your device is installed. Apple->About This Mac->System Report->Software->Extensions
Connect the Rane USB device to the computer. Verify that the computer recognized the connection indicated by the blue LED on the device.
Open Serato DJ.
If Serato DJ does not establish a connection to the device, try hot-plugging the device while Serato DJ is open.
If Serato DJ still does not establish a connection to the device, please email your system report to us. Apple->About This Mac->System Report->File->Save