My MacBook Pro checked out recently. I copied my Lightroom catalog from that computer to an external hard drive before it passed and am attempting to transfer the catalog to my new iMac. The catalog appeared to transfer well but all of the photos are shown as missing (a few half-baked previews did appear but I was unable to view the image). I have question marks and exclamation all over my screen. I've attempted to Find Missing Photos but a message shows that the Original Files cannot be found. I tried redirecting it back to the catalog on my external drive but cannot select it. Nothing I've found online has solved the problem. Any ideas? Thanks.
You have to have more than just the catalog. The catalog is a database that holds a reference to the photos, but it does not hold the photos. You need the photos from the old computer as well. Here are instructions on how to move everything from an old computer to a new one: