I’ve been dabbling in React and recently discovered the amazing create-react-app tool. Here’s a unique problem I ran into when using it, and my solution.

  1. In Visual Studio Team Services (VSTS), I created a new project called “My Project”. The space is important.
  2. VSTS will create a default git repository using the same name as the project.
  3. I pushed the React app to source control.
  4. The repo URL is (notice the encoded space), so cloning it will put it into a My%20App directory.
  5. Run npm start
  6. In terminal, you’ll see the error: "Failed to decode param '/%PUBLIC_URL%/favicon.ico' and 400 bad request errors in the developer console.


The solution is simple, but not immediatley obvious. The % in the file path was breaking the build task searching for the %PUBLIC_URL% tokens in index.html.

My fix was to rename the project folder. I also renamed the repo to spare the rest of the devs on my team.