Black bands on pictures in Lightroom Classic

[jennieb24]

When I installed Lightroom Classic to a new computer many photos have black bands across them.  Photos are stored on Lacie.  They are ok in Lightroom.  Any thoughts on how to resolve problem?  If I uninstall and reinstall will my edits be saved?

[Victoria Bampton LR Queen]

Is the black band in Library module or Develop module?

[jennieb24]

It's in the library mode.  I can see the photos in Lightroom but Lightroom Classic seems to be corrupted.  What to do?

[dj_paige]

Library mode uses previews stored on one of your hard disks, perhaps the previews are corrupted. What happens if you select one of these photos and then Library->Previews->Build 1:1 Previews?

[jennieb24]

First photo came back with 1:1 preview so did 1:1 previews for whole catalogue.  However when I double clicked or moved to Develop the black came back. Other photos which looked ok in grid were corrupted when opened.  However if I use finder to open photo and email that seems better.  I had 44K in catalogue but now number shows as 38K!?

[dj_paige]

If the problem appears in develop, then the file is corrupted. You want to restore these files from your backups.