screen saver not working

Try a restart.

Do a backup, using either Time Machine or a cloning program, to ensure files/data can be recovered. Two backups are better than one.

Try setting up another admin user account to see if the same problem continues. If Back-to-My Mac is selected in System Preferences, the Guest account will not work. The intent is to see if it is specific to one account or a system wide problem. This account can be deleted later.

Isolating an issue by using another user account

If the problem is still there, try booting into the Safe Mode using your normal account. Disconnect all peripherals except those needed for the test. Shut down the computer and then power it back up after waiting 10 seconds. Immediately after hearing the startup chime, hold down the shift key and continue to hold it until the gray Apple icon and a progress bar appear. The boot up is significantly slower than normal. This will reset some caches, forces a directory check, and disables all startup and login items, among other things. When you reboot normally, the initial reboot may be slower than normal. If the system operates normally, there may be 3rd party applications which are causing a problem. Try deleting/disabling the third party applications after a restart by using the application un-installer. For each disable/delete, you will need to restart if you don't do them all at once.

Safe Mode

Safe Mode - Mavericks

Go to Finder and select your user/home folder. With that Finder window as the front window, either select Finder/View/Show View options or go command - J. When the View options opens, check ’Show Library Folder’. That should make your user library folder visible in your user/home folder. Select Library. Then go to Preferences/com.apple.screensaver.plist. Move the .plist to your desktop.

Restart the computer, open the application, and test. If it works okay, delete the plist from the desktop.

If the application is the same, return the .plist to where you got it from, overwriting the newer one.

Thanks to leonie for some information contained in this.

You are welcome.

Problem:

ScreenSaver doesn't display any photos, including the supplied images or their folders; Just an infinite "Loading Photos..." message. The "Flurry" and "Word of the Day" work fine.

I've had this issue for a long time, hoping the last 2 OS versions, as well as the latest Sierra-beta, would fix it. Pointing to a folder of just 7 images didn't make a difference. Deleting and swapping preference files didn't help. I was at my wit's end.

After letting it sit for 3 hours with "Loading Photos..." they appeared! The problem was when I went to preview it, it started searching all over again. My biggest clue was it didn't happen after making a new user, its screensaver was instantaneous. It had to be in my home area.

It occurred to me the Mac wasn't lying, it was searching, probably because I have a boat-load (10Gb) of images. For some reason, it insists on finding every image on my hard drive, although I just wanted 7.

Solution:

I made a disk image (.dmg) in Disk Utility (menu File/New Image). I made a blank one, about twice the size I needed just in case I collect many more photos. This may take a few minutes to create. Move your images into the DMG, (after double checking they're healthy in their new location), I deleted them from their original location.

Your Mac sees DMG "drives" as a single, albeit huge, file and doesn't bother to search it unless directed. It worked instantly.

Now, I keep a folder of 2,000 images in the Art folder for use as an easy to access and edit screensaver location.

Epilogue:

Looking back, having 20,000 images (10Gb) out in the open, on the main drive, was a stupid move. I did it thinking it would be faster on the main drive. Wrong. The Mac needs the main drive to operate from, but by having them still on the main drive but in a DMG, the speed is there, it's just not searched.

Last year, I went to my GP for an issue and he referred me to a specialist. After describing my concern and how it happens, thinking it's going to mean a $5,000 surgery to fix it, quite seriously he said, "Don't do that. Stop hurting yourself. Your body has a way of healing itself. Allow it to do so. You'll be fine in about 2 months, just stop doing it. For now, these over the counter meds will help." I left very happy ...and feeling very stupid."

Stop taxing your Mac and complaining it's slow. I've had Macs since Performa days. If you have a problem and you have endless spinning beach balls, what was the last thing you did before this happened? If you're not sure, allow it to spin and see if it works itself out; it usually does, something was slowing it down. When you find the slow down, just, "Stop doing that."