Why do you need to open a backup?
For LR to be able to access a backup you need to unzip it first.
Wow is it that simple!
I would have thought if LR made the file it would automatically unzip it itself.
I will give it a try. Thanks for your help.
I just tried the unzip and directed it to go to LR6 but it didn't work.
The reason I need to open a backup was when I started LR after the upgrade it couldn't find the Catalog and prompted me to locate it. Its not recognising the file.
Before opening a backup, please search your disc for any lrcat file. If you did not move the catalog, here are the default locations: https://helpx.adobe.com/lightroom/kb/preference-file-and-other-file-locations---lightroom- 6.html
What is the message appearing when you try to open the catalog?