I can't seem to get a 6.5 server to install into my 4.2 tree where 3 other
4.2 servers live. When I get to the point in the 6.5 installation where I
can "create a new tree", or "install into an existing tree", I get an error
that states they can't communicate with each other, make sure all the
protocols are installed the same and correctly.

The 6.5 server can see the 4.2 tree, but when I try to log into it, I get
that protocol error.

I really, really would like to get the 6.5 server into the 4.2 tree, is
this even possible?