cofactors.txt: 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/doc/r-cran-qtl/examples/bin/test/cofactors.txt - from package: r-cran-qtl
/usr/share/doc/r-cran-qtl/examples/bin/test/t11/cofactors.txt - from package: r-cran-qtl
/usr/share/doc/r-cran-qtl/examples/bin/test/t12/cofactors.txt - from package: r-cran-qtl
/usr/share/doc/r-cran-qtl/examples/bin/test/t22/cofactors.txt - from package: r-cran-qtl
/usr/share/doc/r-cran-qtl/examples/bin/test/t23/cofactors.txt - from package: r-cran-qtl
/usr/share/doc/r-cran-qtl/examples/bin/test/t33/cofactors.txt - from package: r-cran-qtl

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

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