The error “Property does not exist on type jsx.intrinsicElements” occurs when you try to use an element that is not defined in the jsx.intrinsicElements property., The error "Property does not exist on type 'JSX.IntrinsicElements'" occurs when a component's name starts with a lowercase letter. To solve the error, make sure to always start component names with a capital letter, install the types for React and restart your dev server., I just started using react-three-fiber yesterday and thought I was losing my mind, glad I'm not the only one having this issue. Here's what worked for me. You'll need to put this in a file somewhere (e.g. a types.d.ts file). Make sure to configure typeRoots in tsconfig.json to include the directory where you put the file, This means that the IntrinsicElements interface we define will merge with the one that TypeScript already knows about. If you try to use an element that isn't defined on JSX.IntrinsicElements, you'll get an error: Property 'X' does not exist on type 'JSX.IntrinsicElements'. const Component = () => { return ;, It's true, that if you use this rule in your eslint, it does raise an error, though typescript itself has no issues with it. The reason this fix works is because it extends the existing namespace for JSX to include any custom web components., After upgrading to React 19, it started giving an error "Property *** does not exist on type JSX.IntrinsicElements" for components react-three-fiber..