That file also works fine for me, whether I use remove all or individually remove the measurements. What happens when you try it? If you look at the REW log files afterwards (their location is shown in the Help -> About REW box) have any errors been logged?
Thanks Arnaud, glad that's all it was - I noticed the button swap as well, it seems something has changed inside the JRE as I haven't made any change. Edit:Actually on investigation turns out this was a side effect of something I did, I've fixed it for the next beta, sorry.
@giordy60: Clarity, Definition and Centre Time are ISO3382 acoustic parameters that have been added in beta 3 and beta 4.