flutter web on GitHub Pages not showing content

Question

I am trying to release my existing flutter project on the web (it already is working on iOS and android).

According to this great article: How to embed your Flutter app in WordPress

I got to the point where I copied the build/web folder to my repository and pushed to master. I ensured everything exist in the repository.

yet NOTHING APPEARS on https://username.github.io/app_folder

Just a blank page :(

Solution

Found the problem in: repository_folder/app_folder/index.html

When I deleted the following line, everything worked:

<base href="/">