You can also try and do a clean install:
Uninstall V-Ray. After that , please check if there are any script files left in “C:\Program Files\Autodesk\3ds Max XXXX\scripts\startup” that have names starting with “vray” (i.e. vrayutils.ms, vrayinstall.ms, vraysceneexport.ms vraylightlister.ms)
and “C:\Program Files\Autodesk\3ds Max XXX\scripts\V-Ray”. If there are such files please remove them.
If that doesn’t help you should contact Thinkbox.