Update mBlock 3 for 64bit mac version


As we know, for the next mac os (Catalina) all software must be in 64bit version, and the latest mBlock 3 (v 3.4.12) still in 32bit. So please update to 64bit.
Or someone please make hardware extension for arduino nano for mBlock 5.


Hi, mBlock 3 is compatible with both 32bit and 64bit.