Under OpenSUSE 11.x and Plesk 9.x and above yast might not work anymore. This probably happens due to a faulty Plesk file.
The error message in the console looks as follows:
suse-server:~ # yast
//sbin/yast: line 27: //lib/YaST2/bin/yast2-funcs: No such file or directory
//sbin/yast: line 238: set_lang_from_sysconfig: command not found
//sbin/yast: line 267: check_ncurses: command not found
package yast2-qt is not installed
package yast2-gtk is not installed
Something is wrong with the YaST user interface.
In the file:
change the first line from
if echo "$MANPATH" | tr ':' '\012' | fgrep -qx //man
if echo "$MANPATH" | tr ':' '\012' | fgrep -qx /usr/share/man
After logging in again via SSH yast will be working again.