atril-previewer: 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/atril-previewer - from package: atril

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

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