As far as I can tell server-side (read: dedicated server) lua errors don't print to chat anymore (assuming they ever did, but I'm pretty sure they did at one point). They do still print into the server console but it's only there for a fraction of a second which makes it infeasible to debug via the console printout. This makes it extremely frustrating to debug errors that crop up during gameplay as I have no way outside of context-guessing to figure out what exactly broke, especially if these are errors that only crop up in multiplayer.