solid-network: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/solid-network - from package: kdebase-workspace

You may install the required package with command yum install {package}
Error in other languages:
solid-network: bevel nie gevind nie
solid-network: comandă negăsită
solid-network: comando não encontrado
solid-network: commande introuvable
solid-network: command not found
solid-network: käsku ei ole
solid-network: không tìm thấy lệnh
solid-network: komanda nerasta
solid-network: Kommando nicht gefunden.
solid-network: kommandot finns inte
solid-network: komut yok
solid-network: nie znaleziono polecenia
solid-network: níor aimsíodh an t-ordú
solid-network: no se encontró la orden
solid-network: no s'ha trobat l'ordre
solid-network: opdracht niet gevonden
solid-network: parancs nem található
solid-network: perintah tidak ditemukan
solid-network: príkaz nenájdený
solid-network: příkaz nenalezen
solid-network: команда не найдена
solid-network: командата не е открита
solid-network: 命令找不到
solid-network: コマンドが見つかりません