The ["scheduling profiler"](https://github.com/facebook/react/tree/master/packages/react-devtools-scheduling-profiler) (live at [react-scheduling-profiler.vercel.app](https://react-scheduling-profiler.vercel.app)) was broken by recent changes to how lanes work in concurrent mode. This was first reported by an engineer at Facebook on Apr 7, 2021.
The "scheduling profiler" (live at react-scheduling-profiler.vercel.app) was broken by recent changes to how lanes work in concurrent mode. This was first reported by an engineer at Facebook on Apr 7, 2021.