FTP is refusing connections

[Omar Abdallah Shaaban]

apt-get install sbcl
Reading package lists... Done
Building dependency tree
Reading state information... Done
sbcl is already the newest version (2:1.4.5-1).
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] y
Setting up hyperspec (1.31) ...
No or old version of the hyperspec found. Getting newer version
Downloading the hyperspec from the Internet
--2019-09-11 12:02:49-- ftp://ftp.lispworks.com/pub/software_tools/reference/HyperSpec-7-0.tar.gz
           => ‘/root/tmp/HyperSpec-7-0.tar.gz’
Resolving ftp.lispworks.com (ftp.lispworks.com)... 92.243.11.64
Connecting to ftp.lispworks.com (ftp.lispworks.com)|92.243.11.64|:21... failed: Connection refused.
Unable to download and can't ask whether to try again.
dpkg: error processing package hyperspec (--configure):
 installed hyperspec package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
 hyperspec
E: Sub-process /usr/bin/dpkg returned an error code (1)