mac Photo

That is very odd. The only thing similar I've heard recently is use of the re-touch tool not being exported.

The workaround for that was to export while in edit mode.

Can you try a non retouch edit, but make it excessive - eg contrast up to maxium, which should make a very noticable (and ugly :-) Change (you can always revert it afterwards).

Then trying to export that and see what happens.

If it still is not exporting then try restarting your mac in safe mode and then trying.

Then restart normally, and try again.

Safe mode will clear temporary files and caches, and sometimes fixes odd glitches such as this.

Start up your Mac in safe mode – Apple Support (UK)

Hi

That means the photos library is stored on the external hard drive.

We need to know what format the drive is. You can check that by slecting the drive in finder and opening the info pane (CMD-i)

It should be formatted APFS, or MacOS extended, and have the ignore ownership option checked. You also need to have the hard drive connected before you log on to your mac.

Can you tell us more about your Photos Library?

You wrote "I can import RAW images from my camera to my hard drive via photos". How are you importing? Is Photos copying the photos into the Photos Library on import or are the photos referenced in the original location? Is your Photos Library stored on your Pictures folder, or have you moved it to an external volume? Are you using iCloud Photos or are all photos stored locally?

Hi

How are you exporting? Drag drop? File>export? File>export unmodified original? Or some other way?