I'm running react 16.12.0, react-dom 16.12.0 and scheduler 0.19.1.
On a production build, when I view Profiler tab it says:
Profiling not supported.
Profiling support requires either a development or production-profiling build of React v16.5+.
Learn more at fb.me/react-profiling.
And on a development build, I get this popup when I try to access React DevTools. The console doesn't show the Profiler tab either.
The Profiler component in React was introduced in version 16.5, which means that you need at least version 16.5 of React to use it. In your case, you're running version 16.12.0 of React, which is a newer version, but still below the required 16.5.
To enable profiling, you need to update your React version to at least 16.5. You'll also need to make sure that you're building your application in development or production-profiling mode, as the error message suggests. This will enable the necessary code to support the Profiler component.
To update your React version, you can run the following command in your terminal:
npm install --save react@16.5.0This will update your React package to version 16.5.0, which includes support for the Profiler component. Once you've updated your React version, make sure to rebuild your application in development or production-profiling mode, depending on whether you're working locally or deploying to production.
If you're still having trouble with the Profiler component after updating your React version and rebuilding your application, you may need to check that you have the latest version of the React DevTools extension installed in your browser.