Crashes with error
java.lang.NoSuchMethodError: 'net.minecraft.class_47 net.minecraft.class_47$class_48.method_309(net.minecraft.class_2960)' at org.samo_lego.simplevillagers.block.entity.IronFarmBlockEntity.produceIron(IronFarmBlockEntity.java:83) at org.samo_lego.simplevillagers.block.entity.IronFarmBlockEntity.serverTick(IronFarmBlockEntity.java:63)

Server details:
Details: Minecraft Version: 1.20.4 Minecraft Version ID: 1.20.4 Operating System: Linux (amd64) version 5.15.0-58-generic Java Version: 17.0.5, Eclipse Adoptium Java VM Version: OpenJDK 64-Bit Server VM (mixed mode, sharing), Eclipse Adoptium Memory: 3661073920 bytes (3491 MiB) / 8657043456 bytes (8256 MiB) up to 12884901888 bytes (12288 MiB) CPUs: 4 Processor Vendor: GenuineIntel Processor Name: QEMU Virtual CPU version 4.2.0 Identifier: Intel64 Family 6 Model 58 Stepping 9 Microarchitecture: Ivy Bridge (Client) Frequency (GHz): -0.00 Number of physical packages: 4 Number of physical CPUs: 4 Number of logical CPUs: 4 Graphics card #0 name: unknown Graphics card #0 vendor: unknown Graphics card #0 VRAM (MB): 0.00 Graphics card #0 deviceId: unknown Graphics card #0 versionInfo: unknown Virtual memory max (MB): 8000.75 Virtual memory used (MB): 9646.04 Swap memory total (MB): 0.00 Swap memory used (MB): 0.00 JVM Flags: 2 total; -Xmx12G -Xms4G Fabric Mods: architectury: Architectury 11.1.17 biomesoplenty: BiomesOPlenty 19.0.0.63 com_electronwill_night-config_core: core 3.6.7 com_electronwill_night-config_toml: toml 3.6.7 net_jodah_typetools: typetools 0.6.3 bookshelf: Bookshelf 23.0.6 cloth-config: Cloth Config v13 13.0.121 cloth-basic-math: cloth-basic-math 0.6.1 darkutils: DarkUtilities 19.0.6 fabric-api: Fabric API 0.96.11+1.20.4 fabric-api-base: Fabric API Base 0.4.36+78d798af4f fabric-api-lookup-api-v1: Fabric API Lookup API (v1) 1.6.49+82b1bb3e4f fabric-biome-api-v1: Fabric Biome API (v1) 13.0.16+78d798af4f fabric-block-api-v1: Fabric Block API (v1) 1.0.16+3e2216cb4f fabric-block-view-api-v2: Fabric BlockView API (v2) 1.0.4+78d798af4f fabric-command-api-v1: Fabric Command API (v1) 1.2.41+f71b366f4f fabric-command-api-v2: Fabric Command API (v2) 2.2.20+78d798af4f fabric-commands-v0: Fabric Commands (v0) 0.2.58+df3654b34f fabric-containers-v0: Fabric Containers (v0) 0.1.86+df3654b34f fabric-content-registries-v0: Fabric Content Registries (v0) 5.0.15+78d798af4f fabric-convention-tags-v1: Fabric Convention Tags 1.5.10+78d798af4f fabric-crash-report-info-v1: Fabric Crash Report Info (v1) 0.2.23+78d798af4f fabric-data-attachment-api-v1: Fabric Data Attachment API (v1) 1.1.4+b90db5744f fabric-data-generation-api-v1: Fabric Data Generation API (v1) 13.2.4+5c0133444f fabric-dimensions-v1: Fabric Dimensions API (v1) 2.1.61+78d798af4f fabric-entity-events-v1: Fabric Entity Events (v1) 1.6.1+09fc25014f fabric-events-interaction-v0: Fabric Events Interaction (v0) 0.7.1+389931eb4f fabric-events-lifecycle-v0: Fabric Events Lifecycle (v0) 0.2.74+df3654b34f fabric-game-rule-api-v1: Fabric Game Rule API (v1) 1.0.46+78d798af4f fabric-item-api-v1: Fabric Item API (v1) 2.2.0+d6f2b0844f fabric-item-group-api-v1: Fabric Item Group API (v1) 4.0.26+58f8c0124f fabric-lifecycle-events-v1: Fabric Lifecycle Events (v1) 2.3.0+a67ffb5d4f fabric-loot-api-v2: Fabric Loot API (v2) 2.1.9+78d798af4f fabric-message-api-v1: Fabric Message API (v1) 6.0.5+78d798af4f fabric-mining-level-api-v1: Fabric Mining Level API (v1) 2.1.65+78d798af4f fabric-networking-api-v1: Fabric Networking API (v1) 3.1.7+2e5ac5484f fabric-object-builder-api-v1: Fabric Object Builder API (v1) 13.0.14+080016e44f fabric-particles-v1: Fabric Particles (v1) 1.1.7+78d798af4f fabric-recipe-api-v1: Fabric Recipe API (v1) 2.0.20+78d798af4f fabric-registry-sync-v0: Fabric Registry Sync (v0) 4.0.19+58f8c0124f fabric-rendering-data-attachment-v1: Fabric Rendering Data Attachment (v1) 0.3.42+73761d2e4f fabric-rendering-fluids-v1: Fabric Rendering Fluids (v1) 3.1.1+e761c6694f fabric-resource-conditions-api-v1: Fabric Resource Conditions API (v1) 2.3.14+78d798af4f fabric-resource-loader-v0: Fabric Resource Loader (v0) 0.11.20+df798a894f fabric-screen-handler-api-v1: Fabric Screen Handler API (v1) 1.3.55+78d798af4f fabric-transfer-api-v1: Fabric Transfer API (v1) 4.0.11+eb30349a4f fabric-transitive-access-wideners-v1: Fabric Transitive Access Wideners (v1) 5.0.14+78d798af4f fabricloader: Fabric Loader 0.15.7 mixinextras: MixinExtras 0.3.5 ferritecore: FerriteCore 6.0.3 forgeconfigapiport: Forge Config API Port 20.4.3 glitchcore: GlitchCore 1.0.0.59 huskhomes: HuskHomes 4.6.1 adventure-platform-fabric: adventure-platform-fabric 5.11.0 net_kyori_adventure-api: adventure-api 4.15.0 net_kyori_adventure-key: adventure-key 4.15.0 net_kyori_adventure-platform-api: adventure-platform-api 4.3.2 net_kyori_adventure-text-logger-slf4j: adventure-text-logger-slf4j 4.15.0 net_kyori_adventure-text-minimessage: adventure-text-minimessage 4.15.0 net_kyori_adventure-text-serializer-ansi: adventure-text-serializer-ansi 4.15.0 net_kyori_adventure-text-serializer-gson: adventure-text-serializer-gson 4.15.0 net_kyori_adventure-text-serializer-json: adventure-text-serializer-json 4.15.0 net_kyori_adventure-text-serializer-plain: adventure-text-serializer-plain 4.15.0 net_kyori_ansi: ansi 1.0.3 net_kyori_examination-api: examination-api 1.3.0 net_kyori_examination-string: examination-string 1.3.0 net_kyori_option: option 1.0.0 com_h2database_h2: h2 2.2.220 com_mysql_mysql-connector-j: mysql-connector-j 8.3.0 fabric-permissions-api-v0: fabric-permissions-api 0.2-SNAPSHOT org_apache_commons_commons-pool2: commons-pool2 2.12.0 org_mariadb_jdbc_mariadb-java-client: mariadb-java-client 3.3.2 org_xerial_sqlite-jdbc: sqlite-jdbc 3.45.0.0 placeholder-api: Placeholder API 2.3.0+1.20.3 redis_clients_jedis: jedis 5.1.0 java: OpenJDK 64-Bit Server VM 17 lithium: Lithium 0.12.1 minecraft: Minecraft 1.20.4 openpartiesandclaims: Open Parties and Claims 0.20.4 pfm: Paladin's Furniture 1.2.1 pigpen: PigPen 17.0.3 roughlyenoughitems: Roughly Enough Items 14.0.688 error_notifier: Error Notifier 1.0.9 runelic: Runelic 21.0.3 simplevillagers: Simple Villagers 1.4.6 config2brigadier: Config to Brigadier 1.2.5 terrablender: TerraBlender 3.3.0.12 universal-graves: Universal Graves 3.2.1+1.20.3 common-protection-api: Common Protection API 1.0.0 polymer-core: Polymer (Core) 0.7.5+1.20.4 polymer-networking: Polymer (Networking) 0.7.5+1.20.4 polymer-registry-sync-manipulator: Polymer (Registry Sync Manipulator) 0.7.5+1.20.4 polymer-resource-pack: Polymer (Resource Pack) 0.7.5+1.20.4 polymer-virtual-entity: Polymer (Virtual Entity) 0.7.5+1.20.4 polymer-common: Polymer (Common) 0.7.5+1.20.4 packet_tweaker: Packet Tweaker 0.5.1+1.20.4 predicate-api: Predicate API 0.3.0+1.20.2 server_translations_api: Server Translations API 2.2.0+1.20.3-rc1 sgui: sgui 1.4.1+1.20.4 xaerominimap: Xaero's Minimap 24.0.3 xaeroworldmap: Xaero's World Map 1.38.1 Server Running: true Player Count: 2 / 12; [class_3222['Chosee'/4, l='ServerLevel[world]', x=-595.67, y=95.17, z=1292.99], class_3222['Superni4'/43524, l='ServerLevel[world]', x=-494.76, y=94.00, z=1332.97]] Data Packs: vanilla, fabric, biomesoplenty (incompatible), bookshelf (incompatible), config2brigadier, darkutils (incompatible), fabric-convention-tags-v1, openpartiesandclaims (incompatible), pfm, runelic (incompatible), server_translations_api, simplevillagers, terrablender (incompatible), universal-graves, pfm-data-resources Enabled Feature Flags: minecraft:vanilla World Generation: Stable Is Modded: Definitely; Server brand changed to 'fabric' Type: Dedicated Server (map_server.txt)

Also is there any plan to update to latest minecraft version? When i tried to add this mod to minecraft client - it crashed and i removed it since it can work serverside only

You're lucky you got the mod to load 🙃. Didn't expect old version to even come that far in 1.20.4 😅.

Sadly I'm not planning to update this anytime soon, as I'm out of time for modding :/. If you know how to code, I'll gladly accept PR fix.