Using LR CC (Windows) for more than a year now, I now faced the problem that LR does not import & copy all of the photos from an external card reader (CF card) to the internal hard disk. For whatever reason, approx. 30 images out of 500 were simply not imported & copied (physically not on the internal HDD, nor in the catalog). All of the images are CR2 files and no error message showed up.
Is it possible that you have previously imported these photos to a different folder?
Then those images are already in the LR catalog file. Even if they do not exist on any drive connected to your computer LR has a record of them in the catalog file.
Take the name of one of those images and in LR input it into the Filter bar and see if they are in the catalog.
Make sure your camera is not set to restart numbering on the filenames every time you reformat the card. On many cameras this is the default setting and can make Lightroom think you already have the photos in your catalog. Lightroom is a tad too quick to think that two files with the same name are the same file and this can lead to lost images. This can be really bad in dual shooter situations if both cameras are numbering more or less the same and you end up with same named images taken at around the same time. If you make sure your camera is set to number consecutively you have a much lower probability of running into this.
Don't know if this is your problem but it is something to watch out for.
Thanks for all the comments.
I never had previously imported the images.
Also, the filenames do not restart with 0001, 0002 etc... every time the card is reformated, so I am pretty sure that the filenames of the missing images are unique. In fact, I checked that the catalog doesn't include images with the same filenames.
I tried to import/copy the images from the CF Card to a new catalog and no problem arised.
Of course importing them into a new catalog works fine because that new catalog has no record of those images ever being imported before.
There is something going on that is making LR think those images are already in your original catalog. In my experience that is because they are in fact in the catalog already.
Do you have the option to show "All Photographs" selected in the Catalog section in the Library module? And not either a drive or folder selected in the Folders area or even a collection selected when you are using the filter bar to search for one of those file names. all of that on the left hand panel of the Library module.
I agree with Just Shoot Me, this means almost always that the images are already there, so make sure to really check and search in "All photographs". If you are convinced they are not there, than there is a problem with your catalog and I would make sure to validate its integrity. You do this by restarting Lightroom and holding the alt/option key. You will get a dialog where you can check the integrity of the catalog. You also should optimize the catalog from the File menu.
I shoot both JPG and RAW Cr2 files.
I noticed this yesterday after shooting a job and saw that on some images only the JPG was imported and some files skipped altogether.
Re-inserting the card brought up the import dialog with the already imported images grayed out as usual but showing the files that had not been imported which I could then import.
When I imported the files they displayed the JPG+Cr2 file next to the plain JPG file. Both had the same number.
The cards are from two different cameras.
I am using a 27" iMac Late 2012, 32 GB RAM