In a large server (such as the official one where this issue was noticed) having a large quantity of RFTools receivers causes the dialer to kill the server when opened. If you don't close the GUI before the list is visible, the server is dead until it either crashes, or restarts. I would show footage, but the server is currently completely dead in the water right now because I attempted to use a dialer again 40 minutes ago. The simplest way to reproduce it however, is to go into the official server, place a dialer, and right click it. (I am unsure how many receivers are needed to kill it, but the server has definitely hit it.) This also renders RFTools Dimensions completely useless, as there is no way to otherwise access a dimlet without a dialer.

Nevermind, turns out there was some receiver sending an absurd amount of NBT data each time it was opened, so the issue is fixed lol.