Official comment
You should check that the DDJ is recognized by the computer. With the DDJ powered-on and connected to the computer, click on the Apple icon at top left, and go to About this Mac and click System Report. From the System Information window, click the USB item at the left and expand any items at the top right to see if the DDJ-1000 appears on the list. If it does, the device is okay - you can try downloading and installing the firwmare again, but if it doesn't run, you'll need to contact Pioneer DJ technical support in your region to have your DDJ inspected and/or serviced.