Strange issue with Lightroom on a Mac

[DerekRiehm]

This problem just cropped up.  I have 25,000+ photos in a single LR catalog, running on a Mac.  I have recently upgraded both the operating system and LR (to 6.8).

I just noticed that Lightroom is making changes to photos that I haven't edited for a long time.  When I go into a folder with photos from, say, 2013, Lightroom changes all photos to a 4X3 crop and makes changes to the exposure settings as well.

If I go to my backed up catalogs, it appears I have to go back at least six weeks (which was prior to both upgrades) so that this doesn't happen.  Of course I can use a backed up catalog and transfer my recent photos from my current catalog to the backed up catalog, then switch over to it, so that I don't have to manually edit the photos that LR has altered.  But there is no guarantee this won't be repeated when I save the new catalog.

I haven't gotten very far into investigating this yet, but I thought I would post this to see if any other LR/Mac users have run into the same problem?

[Just Shoot Me · Accepted solution]

Two things to try.

Reset the LR preferences. http://www.lightroomqueen.com/articles-page/how-do-i-reset-lightrooms-preferences/

In the Develop module open the develop menu item and select Set default Settings. When the dialog box opens select "Restore Adobe Default Settings".

[DerekRiehm]

Tried the second suggestion and that seems to have fixed the problem.  Thanks a lot!

[Just Shoot Me]

You're welcome.

[DerekRiehm]

I spoke too soon.  The problem has not been fixed.  Unbelievably, LR is still auto-cropping my photos to 4X3.

It seems that the issue is confined to photos that I shot with a Nikon D600 that I used from late 2012 to early 2014.  Photos taken before that period, which were a mixed bag of point & shoots, scans and a low-end Canon DSLR, are unaffected.  Photos I have taken since early 2014, when I upgraded to a Nikon D800, are similarly unaffected.

This has me shaking my head.  Does anyone have any suggestions?

[Just Shoot Me]

Select one of those images and do the same process. I also suggest you delete the LR preference file once you have reset the Default develop settings. Close LR and delete the preference file.

[DerekRiehm]

Deleting the LR preference file seems to have done the trick.  Fingers crossed.  Thanks for your help, and happy holidays.