by Julieanne Kost
If you move files on your hard drive(s) using the operating system after importing them into Lightroom (essentially, moving files behind Lightroom’s back), Lightroom will lose the link (or the “path”) to the files and display a warning icon next to the image in the Grid view. Depending on whether or not the image had a Smart Preview built, it will either display a “!” (to let you know that the file is missing and that there was no Smart Preview built) or a rectangle with dots around it (meaning that the image is missing but there is a Smart Preview so you can continue editing it even though it is “off-line”).
Clicking on either of the warning icons will display the following dialog (regardless of the availability of a Smart Preview):
If you don’t remember where you moved the file, drag-select the name of the file and use the following shortcut: Command + C (Mac) | Control + C (Win), to copy the name of the file to the clipboard.
Click OK and in the subsequent dialog, Command + V (Mac) | Control + V (Win), to paste the name into the operating system’s search feature. Once you locate the missing image, be sure to check the option to “Find Nearby Missing Photos” if more than one image from the same folder is missing (the option should be on by default).
Or perhaps this post will be helpful.