After it hits 100%, it might stay dark for a minute or two while it reboots. Don't panic and pull the plug!. Find the official step-by-step guide at the ViewSonic Support Center

The process of updating the ViewSonic M1 Mini is designed to be accessible, though it requires a degree of care to avoid damaging the device. Unlike smartphones that update over the air (OTA) automatically, the M1 Mini typically requires a manual update via a USB thumb drive. This process involves visiting the official ViewSonic support website, locating the specific model, and downloading the latest firmware file—usually contained within a compressed folder.

remove the USB or power cable until the progress bar reaches 100% and the device restarts. Review: ViewSonic M1 mini

Previous firmware treated brightness as a flat line. The new update introduces . When the projector detects a dark scene (like a night shot in Dune ), it reduces LED output to save battery. When it detects a bright sports scene, it overdrives the LEDs for 30-second bursts.