feelpp_ls_laplacian: 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/feelpp_ls_laplacian - from package: feel++-apps

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

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