It errored on first go with a blank screen:

Error: Failed to allocate type at x.allocate (worker-3ec07b2e.js:1:3516) at ImportGlGenTexture (worker-3ec07b2e.js:1:7645) at RaverieEditor-60af6467.wasm:0x1d459ee at RaverieEditor-60af6467.wasm:0xedf9e7 at RaverieEditor-60af6467.wasm:0xedf56b at RaverieEditor-60af6467.wasm:0xdffefa at RaverieEditor-60af6467.wasm:0xf213e3

Reloading fixed it, maybe a race condition between setting up the app and it being ready to run.