Page build failure

[kave-me]

I forked your blog, then I just modified CNAME and immediately after that, I received an email from GitHub with the following content:

The page build failed for the master branch with the following error:

The jekyll-theme-mehdix-rtl theme is not currently supported on GitHub Pages. For more information, see https://help.github.com/en/articles/adding-a-jekyll-theme-to-your-github-pages-site.

For information on troubleshooting Jekyll see:

https://help.github.com/articles/troubleshooting-jekyll-builds

If you have any questions you can contact us by replying to this email.

the main Question is that I can't Understand whether the two repositories are identical how it is possible that you are using it without any problem and I cant!

[mehdisadeghi]

The jekyll-theme-mehdix-rtl theme is not currently supported on GitHub Pages.

True.

Github supports a very limited set of plugins and gems during builds, this theme is not one of them.

the main Question is that I can't Understand whether the two repositories are identical how it is possible that you are using it without any problem and I cant!

You are using Github pages, I don't.

Please see this and this.

You should use a custom CI pipeline like Travis, build after each change, and push back to your gh-pages branch. Or serve your site elsewhere, like on Netlify.