I cloned my W7 64 bit and upgraded to Windows 10, all programs other than Lightroom 6 work OK. When selecting Lightroom 6 to run I get "Unexpected error opening catalog. The catalog could not be opened due to an unexpected error".
However on right clicking the lightroom Icon and selecting run as Administrator Lightroom works OK. Not a major inconvenience, but annoying all the same. Any help in sorting this problem would be very much appreciated. All 'permission' are correct compared to to windows 7.
I would suggest you to please uninstall and reinstall Lightroom 6 on the computer.
Please let us know if it helps.