Install libct4 by entering the following commands in the terminal:
sudo apt update sudo apt install libct4
Description:
libraries for connecting to MS SQL and Sybase SQL servers
FreeTDS is an implementation of the Tabular DataStream protocol, used for connecting to MS SQL and Sybase servers over TCP/IP. . This package includes the shared libraries for the Sybase CT-Lib API. You will need this if you plan to connect to MS SQL or Sybase servers, or use the PHP sybase or Perl DBD::Sybase extensions.
Homepage: http://www.freetds.org/
Version: 1.00.82-2
Section: libs