fatal: bad ownership or modes for chroot directory component "/" in SFTP

Solution 1:

Using ChrootDirectory option in sshd_config requires some basic understanding of written text.

This is snapshot from manual page for sshd_config(5):

ChrootDirectory

Specifies the pathname of a directory to chroot(2) to after authentication. All components of the pathname must be root-owned directories that are not writable by any other user or group. After the chroot, sshd(8) changes the working directory to the user's home directory.

This is your error log:

fatal: bad ownership or modes for chroot directory component "/"

This means that you need to make sure to fulfil the emphasised part of the quote: Your / need to be owned by root and has w acl only for the owner.