In multiplayer games, opening or closing any of the Bibliocraft display cases throws a NullPointerException with a crash warning from the VanillaFix mod, and does not play any audio for the display case. The case opens/closes fine aside from the warning and crash dump, and other audio continues as normal. In single player games the display case opens and closes without error, playing a small hinge noise each time.
For basic debugging, I've tried replacing the server and client both, as well as verified it reproduces in new server worlds. This feels like a Bibliocraft issue at a glance, but starting here since it's a modpack.
Was reported to my modpack over https://github.com/xJon/The-1.12.2-Pack/issues/171: