GSMarkupBrowser: 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/bin/GSMarkupBrowser - from package: librenaissance0-dev

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

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