I have a new Mac and have managed to reinstall everything from my backup Time Machine. However, when I try to edit an image which is in Lightroom in either Photoshop Elements 12 or in one of my Nik plug ins I get the following message:
Lightroom was unable to prepare the selected file at /Volumes/Time Machine Backups/My Lightroom Images/2014/November/20141120-London003.DNG for editing.
It will not be opened.
I wondered whether it was because I have used Elements 12 and the Nik plug ins on two iMacs and am now trying to use them on a third (one of the original Macs has recently died).