Add Photos, Some photos were not added.

On PC w latest Windows 

Plug in SD card with reader 

Click "Add Photos" 

Select D:\blah 

Get a blue highlighted note on upper right of app saying "Add 9 Photos"; click this

Goes through import motions and then says "Some photos not added" with the list of nine stuffed in a temp folder shown in a list under "Duplicate items (9)". 

But... I go to said folder and they are not there, I can't open them, I can't delete them. And this is happening every time. I've closed and-re-opened the app and un-plugged plugged the sd card back in. Haven't re-booted the OS yet or tried anything else more aggressive. 

Would love some help, here's the addy of one of the supposed duplicates in a temp folder: 

C:\Users\rolla\AppData\Local\Adobe\Lightroom CC\Data\Import\Temporary download C6443FCE-BC58-42BD-9CB8-A724BDC077F3\L1010300.JPG