This error appears to be a React initialization failure, but it’s actually (if I’m not wrong) caused by intermittent availability issues with the aistudiocdn.com CDN that serves the import map dependencies. If you’re experiencing persistent issues, you can verify by checking the Network tab in DevTools to see if React is loading successfully from the CDN.
By default, Gemini Pro 3 uses the CDNs from ai-studio which seem unstable, on my side I have manually modified the CDNs for more stability.