I'm not sure what you mean by "downloading 8 originals". Do you mean you're trying to transfer 8 photos/videos from your iPhone or iPad to your Mac using Photos? If so, then left-click and hold the Photos app icon in the dock until a menu pops up, hold the option key on your keyboard, and select Force Quit (or click the Apple menu at top left, then select Force Quit and then Photos. Then try again. If it still is an issue, then you can try AirDropping the photos/videos to your Mac and then importing them into Photos from there.