Can't install any Scratch Plugins on Renoise 3.5 1 - 3.54

Thought I would try some turntable scratch plugins - there is a new free one called turntable saw and I also tried a paid one called scratch track. Renoise does not like it when I try and install them both. They are both VST3 plugins. I am guessing this is a Renoise bug rather than something I am doing wrong?