I have windows 10, and the latest version of Lightroom CC (2015) for Windows. Just today (12/24/2016) I have a the problem where I click the "Import" button and the entire application freezes and the windows taskbar says (Not Responding). I let it sit there for an hour and it didn't do anything and I eventually killed it. I've uniinstalled and re-installed Lightroom but that didn't fix the problem. Did the latest update to Lightroom cc break something?
Can you provide specifics about the Lightroom Import settings that you have selected prior to clicking on the import button?
Were these settings working prior to the update? Also confirm that you are using LR CC 2015.8 which is the latest version.
Are the other functions of Lightroom working e.g the develop module?