May be the presence of virus running in the external drive background.A few reasons behind the error are listed below: The error problem ejecting USB mass storage device means, you will no longer be able to safely remove your storage drive. What causes the problem ejecting USB mass storage device? Hence, it is not advised to unplug the USB storage device when you encounter the error. If you forcefully unplug your USB device regardless of the error, you might get your drive corrupted and put your precious data at risk. Unplugging the USB device when it displays problem ejecting USB mass storage device is certainly unsafe for your important data stored in the drive. Is it safe to unplug the device when it says USB device in use? If you are thinking what is this error and how would you eject USB drive that is showing currently in use, the coming sections helps you clear your queries related to the problem ejecting USB mass storage device. The device ‘Generic volume’ cannot be stopped right now.Close any program using the device and then remove it. Don’t remove the device while it is in use. Close any programs or windows that might be using the device and then try again. The problem could be encountered in different form. The problem while ejecting the USB mass storage not only appears like it is displayed above. How does the USB error appear on the screen? If you have lost data due to the error, this article also helps you to recover data from the USB drive without any hassle. If you are facing the similar error or unable to eject external hard drive, follow the mentioned methods in the article and easily fix the error. Most of the USB users often come across the error problem ejecting USB mass storage device.