Even great software has quirks. Here is a troubleshooting table for version 3.4.12:

: Pinoo Robotics provides a direct overview and legacy download links for v3.4.12, noting its Windows and macOS compatibility.

The mBlock stage UI reflects these values in real-time without the user writing "Send to Serial" blocks.

This is the biggest red flag. Makeblock no longer supports 3.4.12. It will never support Windows 11 perfectly, nor macOS beyond Catalina (32-bit support was dropped). If you encounter a bug, you are on your own.

mBlock 3.4.12 is the final stable release of the classic mBlock desktop environment. It serves as the bridge between visual Scratch-based blocks and professional Arduino C code, making it a "gold standard" for educators and hobbyists using the Makeblock ecosystem. 🛠️ The Core Philosophy: Scratch Meets Arduino

Navigate to the category in the center column. Initialize your new feature Click on the Make a Block button. Name your feature