Dehaze issue

Hey,

I have recently ungraded lightrrom classic to version 11.4.1 and ever since then the dehaze slider is not functioning correctly.  Just the smallest movement left or right of the centre point causes the image to go pitch black.  I have also noticed that any preset that uses dehaze also causes the image to go black.

I have uninstalled and re-installed the softare, but am still having the issue.  

Any ideas on how I can solve this?

TIA