parse-category: command not found

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

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

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 Debian possible default full paths are:

/usr/share/circos/tools/categoryviewer/bin/parse-category - from package: circos-tools

You may install the required package with command apt-get install {package}

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