Your device camera might have to be replaced or you might have a software issue. If it's a software issue; you can do a soft reset by holding down the power button for 8 seconds until the device turns off. If that method doesn't work you can do a hard reset of your device but make sure to perform a backup so you wont lose all of your data. If that method doesn't work you can put your device into recovery mode by holding these buttons at the same time while your device is off; power button, volume up, and home button. Use the volume button to scroll and select the option wipe device/factory reset. Then select all user data and press the power button to confirm. If this method doesn't work you might have to replace the motherboard. You can find replacement guides for the device on this page.
Samsung Galaxy Tab Pro 10.1 Troubleshooting