You could highlight all of the images and press the delete key and choose to have them removed from the catalog. But I don't know if that's going to solve your problem. What you mean when you say that they imported but didn't display properly? What was the problem? If you just remove the images from the catalog they will still be on your hard drive in their original location, and you could import them again.
Please click Previous import for the last imported files in the Library module.
Select all the images and then make a right click (CMD + Click on mac). Click on Remove.
Please make sure that you choose the option correctly for Remove (Removes image only from catalog) and Remove from Disk(It deletes the image from catalog as well as from the computer).
Please let me know if this helps.
I was wondering which would be best. Delete from the catalog, or delete from the drive. I was able to copy all of the original NEF files from the LRCAT and I delete them from disk I could re-import from the them drive. I have no idea why they do not display properly but I figure if I wipe the whole export whatever has caused the images to not display properly will also be deleted... ( You can see the image display problem in this thread: Can LR5 be set to delete image files from my SD cards after import? - Lightroom Forums )
If you choose, Delete from Catalog, it will only delete the image from the catalog and will leave the original file untouched.
If you use Delete from drive, it will remove the image from catalog as well as it will delete the image from the computer.
Please post the screenshot in here to check the issue with the display of the image.
The problem in that thread from the other site is that an old card reader is having problems reading a new SDXC card.
Does this describe your situation?
To make a long story short, I made the mistake of using a SDHC memory card reader to import 277 images from a SanDisk 64GB SDXC memory card.
The result was a wonky LR6 Library display ( Why I do not for the life of me know ) and all of the original NEF files on the memory card corrupted and unreadable.
Those original files did however make it into my LR Catalog in good shape and I have since copied those files off onto a thumb drive.
I would probably leave them there if the import had somehow made my LR6 library display like the image attached to this email.
I was wondering what I should do to correct this. How do I erase all traces of this bad import? Can I delete the whole import at once? Do I just say remove image with all highlighted or do I go the remove from disk option? Will this rid me of whatever corrupted data which is causing this strange display?
Do other folders display properly and only this one shows a mixed Grid/Loupe display? In other words, if you click to Quick Collections then back to Previous Import does the display for this folder look different or better?
I don't see how corrupted images would cause LR to not display it's grid, properly, so I'm suspicious something else is going on. Perhaps you should turn off the GPU in LR / Edit / Prefs / Performance if Macs have that setting.
Same for LR6CC?