Random firmware blogs, torrent sites, or "Unic UC40 software update download" links from unverified forums. Many of these contain malware or files for clone devices.
The most stable and widely cited firmware version for this model is 40N07-EN_150901 Unic Uc40 Projector Software Update Download
The projector should detect the file and begin the installation. during this process, as it can brick the device. Important Considerations Unic Uc40 Projector Software Update Download !!INSTALL!! Random firmware blogs, torrent sites, or "Unic UC40