Not sure if this is the Anti-slime block or not (I have them on Slime islands near by) but I keep crashing (as do others on the server) when at my base which disconnects the player and crashes the server. The player gets this message:

Internal Exception: java.io.IOException: An established connection was aborted by the software in your host machine

Here is the server crash report pastebin: https://pastebin.com/XRah5Uti

EDIT UPDATE: I was using Java 1.8.0.161 and switched back to version 1.8.0._25 and it stopped crashing things on the server. >.> I had switched to the more recent version of Java so I wouldn't crash using the Immersive Engineering manual... ug. Now I need to switch between versions to not crash on either. Anyway, I hope this was helpful and that it allows a fix if one is warranted.

This is indeed an issue with Dark Utilities that can be fixed. I have put out a new version that should solve your crash. Look for 1.8.203 or newer on Curse. Please ask the other players if this update made their anti slime blocks stop working, and if it did make a new issue so I can fix it.