I can not install proftpd. I get the following error messages:

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root@server:/home/brad# apt-get install proftpd
Reading package lists... Done
Building dependency tree
Reading state information... Done
Suggested packages:
proftpd-doc
The following NEW packages will be installed:
proftpd
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 0B/784kB of archives.
After unpacking 2331kB of additional disk space will be used.
X Error: BadDevice, invalid or uninitialized input device 169
Major opcode: 145
Minor opcode: 3
Resource id: 0x0
Failed to open device
X Error: BadDevice, invalid or uninitialized input device 169
Major opcode: 145
Minor opcode: 3
Resource id: 0x0
Failed to open device
Session management error: Authentication Rejected, reason : None of the authentication protocols specified are supported and host-based authentication failed
Preconfiguring packages ...
Selecting previously deselected package proftpd.
(Reading database ... 116567 files and directories currently installed.)
Unpacking proftpd (from .../proftpd_1.3.0-21ubuntu1_i386.deb) ...
Setting up proftpd (1.3.0-21ubuntu1) ...
X Error: BadDevice, invalid or uninitialized input device 169
Major opcode: 145
Minor opcode: 3
Resource id: 0x0
Failed to open device
X Error: BadDevice, invalid or uninitialized input device 169
Major opcode: 145
Minor opcode: 3
Resource id: 0x0
Failed to open device
Session management error: Authentication Rejected, reason : None of the authentication protocols specified are supported and host-based authentication failed
* Starting ftp server proftpd - IPv4 getaddrinfo 'server' error: No address associated with hostname
- warning: unable to determine IP address of 'server'
- error: no valid servers configured
- Fatal: error processing configuration file '/etc/proftpd/proftpd.conf'
[fail]
invoke-rc.d: initscript proftpd, action "start" failed.
dpkg: error processing proftpd (--configure):
subprocess post-installation script returned error exit status 1
Errors were encountered while processing:
proftpd
E: Sub-process /usr/bin/dpkg returned an error code (1)