Is there an upgrade path.. I use a direct copy and not CC.
I have seen that this is a universal problem with lr under Win 10. What can I do?
You should install/repair Microsoft Visual C++ 2012 Update 4 : Download Visual C++ Redistributable for Visual Studio 2012 Update 4 from Official Microsoft Download Center
Also, update to version 6.5 : Keeping Lightroom Up-to-Date