Since updating to V 25.12 the sky replacement no longer works.

Ok so that didn't work, adobe help told me to tick the older GPU mode in technogies preview and that fixed it

Ok Ill give it a try thanks

@pictureworks UK the sky replacement is working fine for me with Photoshop version 25.12, try manually resetting your Photoshop preferences
https://helpx.adobe.com/ie/photoshop/using/preferences.html#Manually
Remember to back up your settings before doing the preference reset
https://helpx.adobe.com/ie/photoshop/using/preset-migration.html