Previews from earlier version of LR lost.

[michaelc84678801]

We recently updated to 2015.8 on OS X 10.9.5

Unable to render previews or even open an earlier version LR catalog.  I have tried uninstalling and reinstalling and reseting preferences via option shift delete (which seems to no longer work).

Please help!
Mike

[michaelc84678801]

Should add: I am corporate client.  And indian help desk would not assist since I don't have the IT dept contact info LR was registered under.

[ManiacJoe]

What do you mean by earlier version?

The catalog used by LR 2015.8 is the same catalog used by all the 6.x versions.

If you are referring to the older 5.x catalogs, those will be migrated to new 6.x catalogs when you open them.

[michaelc84678801]

Strangely enough they don't open though.  LR will re-import the raw files of course but it will not access the previews.  These are 5Ds CR2 files.

[DdeGannes · Accepted solution]

"Strangely enough they don't open though.  LR will re-import the raw files of course but it will not access the previews.  These are 5Ds CR2 files."

When a later version of Lightroom converts an earlier version Catalog e.g LR 5 to LR 6 it creates a copy which is compatible with LR 6 and leaves the LR 5 copy in place.

The Previews files are made compatible with LR 6 and if you need to revert to LR 5 you have that catalog but will have to rebuild the previews.