Light room Classic cc Import hanging up

I am  having a problem with the import function hanging up.  Some never finish importing.  I am running Windows 8.1 I7 intel processor 16GB ram.   My old LR 6 was converted to the new format and is in excess of 300k files.  Imports of new pictures is taking forever.  Some even hang the computer and have caused a reboot. 

Files can get corrupted as well.  I have stopped importing from the memory cards, instead copying files to hard drive and then importing.  Seems to work better. 

Another bug I have noticed is that all files are not imported.  From Saturday night Clemson vs NC State, I took 2095 pictures on one card, when LR was finished importing, it only imported 2075 files.  I might not have noticed but I had sent in pictures Sunday 3:00am and when one of those was missing on the full import, I started looking and found the issue of missing 20 files.  Might never have known.  So I am only copying to HD then doing an import from there.

This seems to be a major bug, I don't know how I would catch missing files.  Also terrible performance when importing files and fetching previews. 

This was not an upgrade.