I had same problem due to SELINUXSELinux.
Please, configure selinuxSELinux properly (restorecon -Rv ~ /. sshrestorecon -Rv ~/.ssh) or disable it (on RedHat, you should edit /etc/selinux/config/etc/selinux/config and reboot the nachinemachine or just type setenfoorce 0 forsetenforce 0 to disable selinux temporarySELinux temporarily until next reboot).