Could you please check and confirm the version of Lightroom you are using?
Which operating system are you using?
Also, could you please change the destination folder and then try to import the files?
It started with LR CC Version 6.1. Attempted to update and problems still happening - reinstalling now via "upload" option on CC
Windows 7 Ultimate
Changing the destination folder did not help.
It's also insanely slow importing.
Profile is not corrupted but it's also custom calibrated for my professional lab.
Import is once again NOT working today. Changing destination folder is not helping.
Husband fixed it. Ran CC cleaner and registry cleaner and it seemed to repair it. Previews, import times, etc, all back to normal.
Just make sure you back up LR first.