Actually, the said server was tested to install PVE 7.2 iso. As the server was over 3 years old since manufacture, the XCC certificate had expired and the certificates were manually installed at the client side and the screenshot method was used to install from http. This post was made to assist others in such a predicament as Firefox and other browsers are frequently changing version numbers.
Please note that PVE 6.4 is still receiving updates from debian repo in the last few days.