@After trying to copy some photos to usb flash drive,some copied,some didn't despite plenty of space left on FD.Now the link has been broken with LR and LR can't access photos/folders in Develop and Print.Have followed all instructions in Help re "Locate missing photos" and "Locate missing folders" and nothing works.Seems the more I try,the more unaffected photos get corrupted.Grateful for any help.
After trying to copy some photos to usb flash drive
If all you did was copy (not move) the photos to a flash drive, the photos should not be disconnected in Lightroom. So perhaps you did something else?
Anyway the instructions for fixing this problem are here: Adobe Lightroom - Find moved or missing files and folders