i just want to install router os 6rc2 on router board RG750G to test it but i found my router board not stable and meet much pronlem in load balance so i want to back to old one 5.18 or 5.22
when i put npk in files and order it to restart refuse to install v 5 without do netinstall caz i met problems in netinstall without serial port

can any one help me to back to old non stable v
thanks for help

it works
but after upload of 5.22 npk package do not reboot
go to system -> Packages -> Downgrade

Bye
Thierry