1.21.1 Summary of Patches - embeddedt/ModernFix GitHub Wiki

mixin.bugfix.fix_config_crashes

Fixes Forge configs occasionally becoming corrupted when launching the game.

mixin.bugfix.missing_block_entities

Hypixel sends chunks to the client that are missing some block entity data, which makes chests etc. appear invisible. This 'fixes' the problem by creating the needed data on the client. Has no effect for properly behaved servers or in singleplayer.

mixin.bugfix.packet_leak

Experimental, not enabled by default. An attempted fix for the memory leak issue that occurs after playing long enough on 1.16.

mixin.bugfix.restore_old_dragon_movement

Fixes MC-272431, which tracks the ender dragon being unable to dive to the portal as it did in 1.13 and older. This causes the dragon to fly quite a bit differently from what modern players are used to and also patches out one-cycling, so it's not enabled by default. Thanks to Jukitsu for identifying the regression in the vanilla code.

mixin.devenv

Patches used when running in a development environment, for speed improvement and/or testing

mixin.feature.blockentity_incorrect_thread

This is a debug option and should not be enabled for regular gameplay. Attempts to detect mods interacting with block entities on the wrong thread and crash the game with more information, rather than an unclear ConcurrentModificationException

mixin.feature.cause_lag_by_disabling_threads

Disables the game's use of worker threads for the server and for chunk rendering. This will make performance worse on almost all hardware, and should only be enabled on a client, when you know exactly what you are doing, and probably only on hardware with very few (2 or less) physical CPU cores. In those rare cases, it can reduce lag spikes since there is less contention over the limited cores.

mixin.feature.direct_stack_trace

Normally off, can be enabled to force the raw stack trace to be dumped to the log when a crash occurs. Occasionally vanilla's crash report system fails to work properly and gives an entirely irrelevant stack trace/report.

mixin.feature.integrated_server_watchdog

Adds the vanilla watchdog to singleplayer worlds as well, but just prints out the stacktraces rather than forcefully terminating the world. This version includes the functionality of Fullstack Watchdog, but the latter is still needed for multiplayer.

mixin.feature.registry_event_progress

Runs the Forge loading screen on a background thread for part of the loading process, to allow progress to be shown while content is being registered. May have compatibility issues with some GPU drivers (e.g. macOS), so do not enable it by default in a modpack.

mixin.feature.remove_chat_signing

Prevents the Minecraft client from obtaining the keypair for chat signing. This disables the client's ability to sign chat messages (like No Chat Reports, but in a simpler, albeit less user-friendly way).

mixin.feature.snapshot_easter_egg

Adds easter egg features (does not affect any vanilla visuals or behavior) when running on a snapshot version.

mixin.feature.spam_thread_dump

To be used for debugging purposes only. Causes a thread dump to be output to the log every 60 seconds. This can help to diagnose unexplained freezes during loading/gameplay.

mixin.feature.spark_profile_launch

If enabled, and a compatible version of Spark is installed, the entire launch sequence will be profiled until the main menu.

mixin.feature.stalled_chunk_load_detection

This option may help to detect the cause of chunkloading freezes. However, leaving it enabled may cause slightly worse performance.

mixin.feature.warn_missing_perf_mods

Shows a warning on startup if other performance mods considered essential and highly compatible are not present

mixin.perf.clear_fabric_mapping_tables

Reduces memory usage by clearing mapping data structures in Fabric Loader that are either redundant or rarely used by mods. Off by default for compatibility reasons.

mixin.perf.clear_mixin_classinfo

Force-loads all mixins when launch finishes and then clears out mixin data structures to remove most of Mixin's memory footprint. Disabled by default for compatibility reasons.

mixin.perf.deduplicate_climate_parameters

Deduplicates climate parameter objects used by the new biome system, can save ~2MB but also slows down datapack reload somewhat.

mixin.perf.deduplicate_location

All versions, but disabled by default due to load time impact. Deduplicates resource location namespaces and paths. This saves RAM but also increases the cost of constructing a new ResourceLocation by quite a bit.

mixin.perf.dynamic_entity_renderers

Constructs entity models the first time they are seen instead of during launch. Some mods are not compatible with this option and will cause EntityRenderer crashes.

mixin.perf.dynamic_resources

All versions. See https://github.com/embeddedt/ModernFix/wiki/Dynamic-Resources-FAQ.

mixin.perf.faster_item_rendering

All versions. Avoids rendering the sides of items in GUIs. (Yes, vanilla appears to do that.)

This can triple FPS with a mod like REI/JEI installed on weaker GPUs, if enough items are visible. Disabled by default since it's new and not tested much, but should be safe. The most likely issue is items being completely invisible in GUIs, or appearing flat in the world.