Project Zomboid Patch Notes

Patch 42.21 September 28, 2026

Characters will now automatically re-equip items after exercise
Updated in-game player map, to remove inaccuracies while exploring
Updated localization system to enable more translatable strings
Updated UI “Spawn Point Selection” preview videos to match Map Glowup
Added a notification for players who try to connect to an MP server with different game version
Improved player pathfinding to avoid trampling farming plants where possible
Characters with the Welder occupation will now start the game with Welding recipes, instead of Blacksmithing recipes
Many more (86!) fluid containers can now be used to purify water in the appropriate oven type
Washing machines will now clean dirty rags, strips, or bandages
Fridges and freezers will now warm gradually on the day the power goes out
Refrigeration is now applied correctly to food items in a bag in a fridge or freezer
Antibiotics can now be packaged using the “pack in box” crafting recipe
Subbiomes on the map now won’t generate trees on dirt
Increased brightness on several lamp/illuminated tiles
Floorboard stash containers found using annotated maps are now more appropriately named
Explosives will now work in basements (!)

Improved server player limit handling, including support for up to 254 players and administrator access when servers are full
Fixed an issue that would cause the client to hang on "Loading Map" forever
Addressed multiple causes of a memory leak that could lead to performance degradation and crashes over time
If you continue to encounter an out of memory error in a new save, please submit a bug report with your logs and profiler video from debug so the team can investigate
Implemented several memory optimisations
Reduced instances of black and gray boxes appearing when travelling quickly through the world
Additional causes of this issue are still being investigated and will be addressed in a future update
Fixed issues that could cause errors during lighting updates.

Fixed percent symbol handling in files
Mods should use %% to display % characters
A temporary workaround was implemented to allow both methods of processing, however mod makers should update their mods to use %% to display % characters going forward as this workaround will be removed in a future unstable update
Error logs will be populated highlighting the error so mod makers can see what needs to be updated going forward
Fixed quick tips displaying % as %%
Added memory debug-information when showing fps debug info

Improved Lua checksum validation for multiplayer anti-cheat
Fixed an issue that caused significant performance problems with chunk unloading on multiplayer servers
This should fix most of the bugs players were getting on high-pop servers due to server lag
Fixed errors and crashes that could occur when selecting Multiplayer while certain languages were selected
Fixed an issue where vehicles could temporarily disappear for players after another player disconnected
Fixed an issue that would allow broken B41 worlds to be hosted on B42 servers
Fixed an issue where players switching from b41 to B42 could be met with a missing menu
Improved memory usage by reusing discarded world data
Fixed a memory leak that could lead to performance degradation and crashes over time
If you continue to encounter an out of memory error in a new save, please submit a bug report with your logs and profiler video from debug so the team can investigate
Fixed a rare exception that could occur during exploration
Added the ability for mods to write .json files
Fixed percent symbol handling in translation files
Mod translations should use %% to display % characters