cannot sync photos from mac to iPhone

If your are using iCloud Photo library everything is the same on all devices once everything is completely uploaded and downloaded - what is the iCloud PHoto library status on each device?

LN

I was used to sync my pictures manually from Photos where I stored all my folders well organized with video and pictures taken with my iPhone but also with other cameras and transferred in Photos.

You used iTunes to sync selected albums to your iPhone, right?

The problem is, if you enable iCloud Photo Library on your iPhone, it will erase all iTunes synced photos and you can only sync your photos to the iPhone using iCloud Photo Library.

If you want to continue to use the selective iTunes sync, disable iCloud Photo Library on the iPhone. You can still use iCloud Photo Library on the Mac. to sync your photos to other devices that are using iCloud Photo Library.

Did you enable iCloud Photo Library on your Mac as well? If you did not yet enable it, keep it off, until you made a backup copy of your Photos Library on an external drive. A local copy of the library or a Time Machine backup will give you more security than the iCloud Photo Library, because the iCloud Photo Library is a mirror of your local copy. If you accidentally change or delete a photo on your Mac, the change will immediately sync to iCloud and all devices, and you cannot recover the deleted photo from iCloud. You need a local backup copy as well.

iCloud Photo Library is not a backup, but a central storage to keep the photo libraries on all devices in sync. You should only use it, if you want your complete Photos Library in iCloud and on your iPhone and other devices. iCloud Photo Library FAQ

Make a test: Can you sync your iPhone, if you connect it again and you disable "Sync Photos" in iTunes? If yes, then the problem is with your Photos Library.

First thing to try. Quit Photos and remove the iPod Photo cache as described here: https://support.apple.com/en-us/HT203156

. Then try to sync again.

Then I disabled iCloud Photo Library on both devices (iPhone and Mac).

How did you disable it on your Mac? Did you have the option "Optimize Mac Storage enabled"? If yes, it is important to first disable the "Optimize" option and wait, until all photos have been downloaded again from iCloud, before you disable iCloud Photo Library. Is that what you have done? See the section "Stop using iCloud" on this Help page: https://help.apple.com/photos/mac/1.0/?lang=en#/phtf5e48489c

I found the ipod cache folders (one from iPhoto and one from Photos) but inside there are also two files from the Apple TV. Shall I remove all?

Remove all iPod Cache folders. They will be recreated when you sync again. The reason for removing them is that they may contain corrupted files.

I saw the option "optimize" but I think I disabled too late after having downloaded the pictures because I noticed that now the amount of the pictures in iCloud Library is really smaller then before..

Did you delete any photos from iCloud Photo Library?

Is the size of the library on your Mac still the same, or also smaller?

If the size of the library on your Mac has changed, do you have a Time Machine backup of your Mac?

You can remove the complete iPod Photo Cache folder and its contents, that is what Apple's documentation is saying. If there is a separate folder "Apple TV Photo Cache" just leave it. This folder should not matter when syncing to an iPhone. Are you also syncing to AppleTV?

They are Unix executables file

The Finder will call many files "Unix executable file", if there is no application installed to open them.

Repair the Photos Library again now, after you removed the files: https://help.apple.com/photos/mac/1.0/?lang=en#/pht6be18f93

restart the MAc, before you try to sync again.

You're welcome 🙂

I'm glad you could rescue your library!