The client has to be updatedThis release changed the pack, and a client older than it is turned away at the door. Update the pack in the launcher before you next join.
Twenty mods that 0.28.2 updated by mistake are back to the versions the world was made with.
The CurseForge pack is published again: one server-only mod had slipped into it.
The full list of changes
01Mods
Structurify, Moog's Structure Lib, Sophisticated Backpacks and seventeen other mods are back on the versions of 0.28.1. Two of them place structures, and the world must keep the versions it was made with.
Iris stays: the Shader Packs button is still in the video settings.
Oil Info runs on the server only again. The scanner still shows the pressure of an oil seep to everybody.