Your Hobby plan is active and your account is in good standing, so the plan upgrade is not the issue here. Both the "Failed to fetch repository files" and "Problem processing request" errors typically occur when the Railway GitHub App does not have access to the private repository. Please ensure you have granted access in GitHub Settings -> Applications -> Railway App -> Configure -> Repository access, making sure genperv1/arac-giris-vercel is included. After that, go to your Railway account settings and unlink then relink the GitHub integration, and try deploying again.