UPDATE [SOLVED]: searching for this problem I stumbled into this thread: https://discussions.apple.com/thread/7045334?start=15&tstart.... . as I'm running windows 10 on a mac using bootcamp, it only took me to rename c:/windows/system32/drivers/AppleHFS.sys to something else, reboot and get truecrypt running as before. only side effect until now: I can't see the mac partition contents in windows.