Could you please let me know the exact version of Lightroom installed on your computer?
Also what is the exact error that you get when working in Lightroom?
when i open the lightroom for first time after i turn on error appear ''sfntread library error'' and the each time i try to choose the book button it appears again. Lightroom cc 2015.6.1
Did you try to uninstall and reinstall Lightroom once?
Uninstalling/reinstalling did not solve the problem.