xmlpatternsvalidator: command not found

Have You tried accessing the binary with the full path?

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 CentOS possible default full paths are:

/usr/lib64/qt5/bin/xmlpatternsvalidator - from package: qt5-qtxmlpatterns-devel
/usr/lib/qt5/bin/xmlpatternsvalidator - from package: qt5-qtxmlpatterns-devel
/usr/bin/xmlpatternsvalidator - from package: qt-devel
/usr/lib64/qt4/bin/xmlpatternsvalidator - from package: qt-devel
/usr/lib/qt4/bin/xmlpatternsvalidator - from package: qt-devel

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/xmlpatternsvalidator - from package: qtchooser
/usr/lib/x86_64-linux-gnu/qt4/bin/xmlpatternsvalidator - from package: qt4-dev-tools
/usr/lib/x86_64-linux-gnu/qt5/bin/xmlpatternsvalidator - from package: qtxmlpatterns5-dev-tools

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