"What's new in Photos" being displayed on each launch
Each time I open Photos.app I get the launch screen "What's new in Photos".
I have a 265Gb Photos library sitting on an external Thunderbolt connected Lacie drive formatted Mac OS Extended (Journaled), with "Ignore ownership on this volume" ticked and with the correct permissions and ownership.
Permissions have also been confirmed as per:
Resolve issues caused by changing the permissions of items in your home folder - Apple Support
I have tried all the suggestions on these forums including removing:
~/Library/Containers/com.apple.Photos
The com.apple.Photos.plist was also removed on subsequent attempts at closing and re-opening Photos.app with no change in behaviour:
rm ~/Library/Containers/com.apple.Photos/Data/Library/Preferences/com.apple.Photos .plist
When I remove the directory: ~/Library/Containers/com.apple.Photos and restart Photos.app I get the splash screen and looking at the preferences in the app I see "Use as System Library" is greyed out meaning it is selected as the System Library. If I close and reopen I get the splash screen again but this time "Use as System Library" is not greyed out meaning the selection has not 'stuck'.
If I convert the binary plist (~/Library/Containers/com.apple.Photos/Data/Library/Preferences/com.apple.Photos.pl ist) to xml I can see the following has been set:
<key>IPXWhatsNewSerialNumber</key>
<integer>1</integer>
I assume this means it should not be showing me the splash screen again. I couldn't see anything in the plist about the System Library setting however.
This was working fine before High Sierra.
Software versions:
OSX - High Sierra 10.13.2
Photos - Version 3.0 (3251.12.190)