There should be an identity file called:
!Boot.Utils.Version/txt
In the VirtualRPC install. Sometimes the RISC OS 6 installer doesn't seem to copy this from the old Boot sequence to the new (I blame the author). Manually copying this file from the old backup Boot sequence created by the RISC OS 6 installer into the current !Boot sequence usually resolves the problem.
However in this case it hasn't and I don't know why
Perhaps something else is wrong somewhere? Perhaps the VRPC isn't installed in the default folder? Ring me during office hours when you are in front of the machine.