This is from the command lookup tool:

boot host

To specify the host-specific configuration file to be used at the next system startup, use the boot host command in global configuration mode. To restore the host configuration filename to the default, use the no form of this command.

boot host remote-url

no boot host remote-url

Syntax Description

remote-url

Location of the configuration file. Use the following syntax:

•ftp:[[[//[username[:password]@]location]/directory]/filename]

•rcp:[[[//[username@]location]/directory]/filename]

•tftp:[[[//location]/directory]/filename]

Defaults

If you do not specify a filename using this command, the router uses its configured host name to request a configuration file from a remote server. To form the configuration filename, the router converts its name to all lowercase letters, removes all domain information, and appends -confg or -config.

Looking at the config, you might have not correctly specified the required file.

regards,

Leo