Update: Quick Fix:

How to setup Vs Code

Today I started a new IONIC REACT App and I kept seeing this my ionic tags had error sin my visual code IDE editor. The error say:

Cannot use JSX unless the '--jsx' flag is provided.ts(17004)

What does this mean? and how you can fix it. To fix it this is what you do:

  1. Open tsconfig.json
  2. Change:
    "jsx": "react-jsx" to "jsx": "preserve"
  3. Save the changes

Now you wont see this error in your VS CODE.

UPDATE: I noticed that when I restart my app, this is what is says:

$ ionic serve
> react-scripts.cmd start
[react-scripts] The following changes are being made to your tsconfig.json file:
[react-scripts]   - compilerOptions.jsx must be react-jsx (to support the new JSX transform in React 17)
[react-scripts] i 「wds」: Project is running at
[react-scripts] i 「wds」: webpack output is served from
[react-scripts] i 「wds」: Content not from webpack is served from G:\SCHOOL\Apps\MathApp2\public
[react-scripts] i 「wds」: 404s will fallback to /
[react-scripts] Starting the development server...


Hope that helps.