We are running version 4.0.0 of vB which has not been patched for some time. Our forum traffic in January was 91,732 unique visits and 334,212 page views. We are having problems with database errors, slow response to page loads and occasional non-loads on some areas. We realise that we need to patch the software -- or can we install a higher version than 4.0.0 as a package?
In preparation we have been reading threads and looking at videos here. We have backed up the site on two remote locations. Any further advice would be very much appreciated as my assistant has ten year old experience with servers and networks.