I was using the repetier server version 1.0.4. When I try to auto-update to the latest version. It keeps on loading but not updating. What shall I do for the autoupdate the server.
You always can manually overwrite with manual installation of new version. This will keep settings in tact. How depends on os you are using. For linux you can send this on ssh which normally works, but depends on why it fails. Anyhow you should see what the problem is then:
sudo /usr/local/Repetier-Server/bin/RepetierInstaller /usr/local/Repetier-Server/etc/RepetierServer.xml