file associations doesnt work in Windows 8.1 (XnViewMP 0.68)

[harumscarum]

1. settings - integration - "run the file association tool" - no effect, nothing starts
2. run Associate files with XnViewMP.exe manually and set all associations, but nothing happens at the end

XnViewMP 64bits, always run As Administrator

any ideas how to fix that?

[xnview]

perhaps a problem in your registry, try to remove the HKL\Software\XnViewMP key