You lose access to the updated cloud material library.
Key features of the official Lumion 12.0 release include:
But as with many high-fidelity software launches, the "perfect" render came with some unexpected bugs. The "Patch Patched" Cycle The story quickly became one of rapid-fire fixes: The Launch Glitch: Almost immediately after the release of Lumion 12.0.1
I can provide more targeted troubleshooting steps based on your experience. Lumion 12 New Top Features You Must Try! - What's New!