The Upload folder for iClousd Photos is missing.

The Upload folder for iClousd Photos is missing. This is flashing on screen of my HP computer Windows 8. It won't go away. It says the folder has been moved or deleted. To Open iCloud to pick and new folder but this does not work. Help! If I go into Task Manager I can end task and this works for a short period after clicking on the icloud icon with a yellow warning sign on it. This is also on the tool bar at the bottom of my screen.