Hi @User, every time I simulate my amplifier design (see below), the

vip

net gets highlighted in red. It's connected to a

sev2diffv

component I made for simulation defined below. Why does this happen?

* single-ended to differential voltage buffer
.subckt sev2diffv vi vc vop von PARAMS: gain=1
EP vop vc vi vc { 0.5*gain}
EN von vc vi vc {-0.5*gain}
.ends