Hello; I have had that same situation; These engines rely on oil to aid compression and help sealing. Your compression will return after a tank or two. In the two or so years that the engine has been sitting, what oil it had in it has evaporated or otherwise escaped leaving a soapy residue to prevent rust, it won't be liquid enough to provide a compression seal.
I have my first ever engine (a Saito 45) it doesn't show any compression either, but I know every part of that engine is in a healthy serviceable condition. I wouldn't hesitate to use that engine, but others have picked it up and spun it over then put it down and told me that it's hooped, or it needs a new exhaust valve, or the ring is broken. Yet it starts first flip and will idle all day at 1800 rpm.