If the audio driver for DDJ/XDJ is not installed/updated properly, the following error appears when you select the ASIO driver for DDJ/XDJ on the Preferences->Audio.
If you cannot select the target ASIO driver due to this error, please uninstall and install the audio driver again.
1. Disconnect your DDJ/XDJ from the computer.
2. Close rekordbox dj.
3. Open the Control Panel and uninstall the DDJ/XDJ driver from "Programs and Features".
4. Reboot Windows.
5. Install an appropriate DDJ/XDJ driver found in the latest rekordbox folder in the computer.
You can find the audio driver in C:\Program Files(or Program Files x86)\Pioneer\rekordbox4.x.x\drivers
6. Connect the DDJ/XDJ to the computer.
7. Launch rekordbox.
Please note: Do not install the driver while running rekordbox dj. It will cause problems while updating the driver.