Bug Report

[plulol]

Description
ImageFrame fails to enable on Paper 1.21.11 due to a missing CraftBukkit class.
All ImageFrame commands then throw internal errors.

Server Software:
Paper 1.21.11 (build 39)
Java 21
Host: Shockbyte (shared)

ImageFrame Version:
ImageFrame 1.9.0.0 (Paper build from Modrinth)

Error:
ImageFrame fails during onEnable with the following error:

java.lang.NoClassDefFoundError: org/bukkit/craftbukkit/v1_21_R7/inventory/CraftItemStack
at ImageFrame-1.9.0.0.jar//com.loohp.imageframe.nms.NMS.getInstance(NMS.java:37)
at ImageFrame-1.9.0.0.jar//com.loohp.imageframe.invisibleframe.InvisibleFrameManager.withInvisibleItemFrameData(InvisibleFrameManager.java:130)
at ImageFrame-1.9.0.0.jar//com.loohp.imageframe.invisibleframe.InvisibleFrameManager.addRecipes(InvisibleFrameManager.java:107)
at ImageFrame-1.9.0.0.jar//com.loohp.imageframe.invisibleframe.InvisibleFrameManager.(InvisibleFrameManager.java:93)
at ImageFrame-1.9.0.0.jar//com.loohp.imageframe.ImageFrame.onEnable(ImageFrame.java:279)

Expected Behavior:
ImageFrame should enable successfully on Paper 1.21.11 as advertised.

Actual Behavior:
Plugin fails to enable; all /imageframe commands throw internal errors.

Downgrading Paper to 1.21.10 fixes the issue.
This appears to be caused by hard-coded CraftBukkit version access (v1_21_R7),
which no longer exists in Paper 1.21.11.

[LOOHP]

You've tried downgrading but have you tried updating Paper?

[s4p1ence]

Any updates on this? Paper 1.21.11 server went to 'stable' builds recently, but this plugin still fails to load. Tested on fresh paper server (build72), Java 21, no other plugins besides ImageFrame.

[LOOHP]

You probably have a different error, can you post that?

[s4p1ence]

Here's the whole console log

[02:23:29] [ServerMain/INFO]: [bootstrap] Running Java 21 (OpenJDK 64-Bit Server VM 21.0.7+6-LTS; Microsoft Microsoft-11369940) on Windows 10 10.0 (amd64)
[02:23:29] [ServerMain/INFO]: [bootstrap] Loading Paper 1.21.11-72-main@cd445fd (2025-12-31T17:02:56Z) for Minecraft 1.21.11
[02:23:30] [ServerMain/INFO]: [PluginInitializerManager] Initializing plugins...
[02:23:30] [ServerMain/INFO]: [PluginInitializerManager] Initialized 1 plugin
[02:23:30] [ServerMain/INFO]: [PluginInitializerManager] Bukkit plugins (1):
 - ImageFrame (1.9.0.0)
[02:23:34] [ServerMain/INFO]: Environment: Environment[sessionHost=https://sessionserver.mojang.com, servicesHost=https://api.minecraftservices.com, profilesHost=https://api.mojang.com, name=PROD]
[02:23:35] [ServerMain/INFO]: Loaded 1470 recipes
[02:23:35] [ServerMain/INFO]: Loaded 1584 advancements
[02:23:35] [ServerMain/INFO]: [ca.spottedleaf.dataconverter.minecraft.datatypes.MCTypeRegistry] Initialising converters for DataConverter...
[02:23:36] [ServerMain/INFO]: [ca.spottedleaf.dataconverter.minecraft.datatypes.MCTypeRegistry] Finished initialising converters for DataConverter in 284,3ms
[02:23:36] [Server thread/INFO]: Starting minecraft server version 1.21.11
[02:23:36] [Server thread/INFO]: Loading properties
[02:23:36] [Server thread/INFO]: This server is running Paper version 1.21.11-72-main@cd445fd (2025-12-31T17:02:56Z) (Implementing API version 1.21.11-R0.1-SNAPSHOT)
[02:23:36] [Server thread/INFO]: [spark] This server bundles the spark profiler. For more information please visit https://docs.papermc.io/paper/profiling
[02:23:36] [Server thread/INFO]: Server Ping Player Sample Count: 12
[02:23:36] [Server thread/INFO]: Using 4 threads for Netty based IO
[02:23:36] [Server thread/INFO]: [MoonriseCommon] Paper is using 1 worker threads, 1 I/O threads
[02:23:36] [Server thread/INFO]: Default game type: SURVIVAL
[02:23:36] [Server thread/INFO]: Generating keypair
[02:23:37] [Server thread/INFO]: Starting Minecraft server on *:27215
[02:23:37] [Server thread/INFO]: Paper: Using Java compression from Velocity.
[02:23:37] [Server thread/INFO]: Paper: Using Java cipher from Velocity.
[02:23:37] [Server thread/INFO]: [ImageFrame] Loading server plugin ImageFrame v1.9.0.0
[02:23:37] [Server thread/INFO]: Server permissions file permissions.yml is empty, ignoring it
[02:23:37] [Server thread/INFO]: Preparing level "world01"
[02:23:37] [Server thread/INFO]: Loading 0 persistent chunks for world 'minecraft:overworld'...
[02:23:37] [Server thread/INFO]: Prepared spawn area in 1 ms
[02:23:37] [Server thread/INFO]: Loading 0 persistent chunks for world 'minecraft:the_nether'...
[02:23:37] [Server thread/INFO]: Prepared spawn area in 1 ms
[02:23:37] [Server thread/INFO]: Loading 0 persistent chunks for world 'minecraft:the_end'...
[02:23:37] [Server thread/INFO]: Prepared spawn area in 1 ms
[02:23:37] [Server thread/INFO]: Done preparing level "world01" (0.365s)
[02:23:37] [Server thread/INFO]: [ImageFrame] Enabling ImageFrame v1.9.0.0

stucks on enabling plugin and never resumes. I primarily run the server on Temurin Java, but here i tried the one from Mojang and it didn't fix anything

[LOOHP]

Does the same version of IF work on 1.21.10?

[snottymoose]

i have the same problem and the latest version of IF works on 1.21.10 but not on 1.21.11

[plulol]

Sorry all, went to spend the new years at my cousins' house for a couple of days.

You've tried downgrading but have you tried updating Paper?

My paper version is 1.21.11 build #39 and the issue still occurs on 1.21.11 build #39, while downgrading to paper 1.21.10 fixes it immediately.

[plulol]

1/1 5:54:15 PM [Info] Please standby while we prepare your server for startup. This might take a few moments.
1/1 5:54:15 PM [System] Server is starting.
1/1 5:54:16 PM [Info] Starting org.bukkit.craftbukkit.Main
1/1 5:54:16 PM [Error] 2026-01-02T01:54:16.745803151Z ServerMain WARN Advanced terminal features are not available in this environment
1/1 5:54:16 PM [Info] [bootstrap] Running Java 21 (OpenJDK 64-Bit Server VM 21.0.7+6-LTS; Eclipse Adoptium Temurin-21.0.7+6) on Linux 6.8.0-85-generic (amd64)
1/1 5:54:16 PM [Info] [bootstrap] Loading Paper 1.21.11-39-main@e5e2c50 (2025-12-12T22:00:30Z) for Minecraft 1.21.11
1/1 5:54:17 PM [Info] [PluginInitializerManager] Initializing plugins...
1/1 5:54:17 PM [Info] [PluginInitializerManager] Initialized 8 plugins
1/1 5:54:17 PM [Info] [PluginInitializerManager] Bukkit plugins (8):
1/1 5:54:17 PM [Info] - AxGraves (1.25.0), Craftable (1.3), ImageFrame (1.9.0.0), InstantRestock (2.6.1), NotBounties (1.22.26), ProtocolLib (5.4.0), SimpleMoreSounds (3.0), voicechat (2.6.7)
1/1 5:54:20 PM [Info] Environment: Environment[sessionHost=https://sessionserver.mojang.com/, servicesHost=https://api.minecraftservices.com/, profilesHost=https://api.mojang.com/, name=PROD]
1/1 5:54:21 PM [Info] Loaded 1470 recipes
1/1 5:54:21 PM [Info] Loaded 1584 advancements
1/1 5:54:21 PM [Info] [ca.spottedleaf.dataconverter.minecraft.datatypes.MCTypeRegistry] Initialising converters for DataConverter...
1/1 5:54:22 PM [Info] [ca.spottedleaf.dataconverter.minecraft.datatypes.MCTypeRegistry] Finished initialising converters for DataConverter in 295.5ms
1/1 5:54:22 PM [Info] Starting minecraft server version 1.21.11
1/1 5:54:22 PM [Info] [01:54:22 INFO]: Loading properties
1/1 5:54:22 PM [Info] This server is running Paper version 1.21.11-39-main@e5e2c50 (2025-12-12T22:00:30Z) (Implementing API version 1.21.11-R0.1-SNAPSHOT)
1/1 5:54:22 PM [Info] [spark] This server bundles the spark profiler. For more information please visit https://docs.papermc.io/paper/profiling
1/1 5:54:22 PM [Info] Server Ping Player Sample Count: 12
1/1 5:54:22 PM [Info] Using 4 threads for Netty based IO
1/1 5:54:22 PM [Info] [MoonriseCommon] Paper is using 1 worker threads, 1 I/O threads
1/1 5:54:22 PM [Info] Default game type: SURVIVAL
1/1 5:54:22 PM [Info] [01:54:22 INFO]: Generating keypair
1/1 5:54:22 PM [Info] Starting Minecraft server on 0.0.0.0:23016
1/1 5:54:22 PM [Info] Paper: Using libdeflate (Linux x86_64) compression from Velocity.
1/1 5:54:22 PM [Info] Paper: Using OpenSSL 3.x.x (Linux x86_64) cipher from Velocity.
1/1 5:54:23 PM [Info] [SpigotLibraryLoader] [NotBounties] Loading 2 libraries... please wait
1/1 5:54:23 PM [Info] [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/com/mysql/mysql-connector-j/9.4.0/mysql-connector-j-9.4.0.jar
1/1 5:54:23 PM [Info] [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/com/google/protobuf/protobuf-java/4.31.1/protobuf-java-4.31.1.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/io/lettuce/lettuce-core/7.0.0.RELEASE/lettuce-core-7.0.0.RELEASE.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/redis/clients/authentication/redis-authx-core/0.1.1-beta2/redis-authx-core-0.1.1-beta2.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/org/slf4j/slf4j-api/1.7.36/slf4j-api-1.7.36.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/io/netty/netty-common/4.2.4.Final/netty-common-4.2.4.Final.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/io/netty/netty-handler/4.2.4.Final/netty-handler-4.2.4.Final.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/io/netty/netty-resolver/4.2.4.Final/netty-resolver-4.2.4.Final.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/io/netty/netty-buffer/4.2.4.Final/netty-buffer-4.2.4.Final.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/io/netty/netty-transport-native-unix-common/4.2.4.Final/netty-transport-native-unix-common-4.2.4.Final.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/io/netty/netty-codec-base/4.2.4.Final/netty-codec-base-4.2.4.Final.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/io/netty/netty-transport/4.2.4.Final/netty-transport-4.2.4.Final.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/io/projectreactor/reactor-core/3.6.6/reactor-core-3.6.6.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/org/reactivestreams/reactive-streams/1.0.4/reactive-streams-1.0.4.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/io/netty/netty-resolver-dns/4.2.4.Final/netty-resolver-dns-4.2.4.Final.jar
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [SpigotLibraryLoader] [NotBounties] Loaded library /server/libraries/io/netty/netty-codec-dns/4.2.4.Final/netty-codec-dns-4.2.4.Final.jar
1/1 5:54:23 PM [Info] [ImageFrame] Loading server plugin ImageFrame v1.9.0.0
1/1 5:54:23 PM [Info] [SimpleMoreSounds] Loading server plugin SimpleMoreSounds v3.0
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [voicechat] Loading server plugin voicechat v2.6.7
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [InstantRestock] Loading server plugin InstantRestock v2.6.1
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [NotBounties] Loading server plugin NotBounties v1.22.26
1/1 5:54:23 PM [Info] [Craftable] Loading server plugin Craftable v1.3
1/1 5:54:23 PM [Info] [01:54:23 INFO]: [ProtocolLib] Loading server plugin ProtocolLib v5.4.0
1/1 5:54:23 PM [Warning] [ProtocolLib] Version (MC: 1.21.11) has not yet been tested! Proceed with caution.
1/1 5:54:23 PM [Info] [AxGraves] Loading server plugin AxGraves v1.25.0
1/1 5:54:23 PM [Info] Server permissions file permissions.yml is empty, ignoring it
1/1 5:54:23 PM [Info] [ProtocolLib] Enabling ProtocolLib v5.4.0
1/1 5:54:23 PM [Info] Preparing level "world"
1/1 5:54:24 PM [Info] Loading 0 persistent chunks for world 'minecraft:overworld'...
1/1 5:54:24 PM [Info] Prepared spawn area in 0 ms
1/1 5:54:24 PM [Info] Loading 0 persistent chunks for world 'minecraft:the_nether'...
1/1 5:54:24 PM [Info] Prepared spawn area in 0 ms
1/1 5:54:24 PM [Info] Loading 0 persistent chunks for world 'minecraft:the_end'...
1/1 5:54:24 PM [Info] Prepared spawn area in 1 ms
1/1 5:54:24 PM [Info] Done preparing level "world" (0.383s)
1/1 5:54:24 PM [Info] [ImageFrame] Enabling ImageFrame v1.9.0.0
1/1 5:54:30 PM [Error] Error occurred while enabling ImageFrame v1.9.0.0 (Is it up to date?)
1/1 5:54:30 PM [Error] java.lang.NoClassDefFoundError: org/bukkit/craftbukkit/v1_21_R7/inventory/CraftItemStack
1/1 5:54:30 PM [Error] at java.base/java.lang.Class.forName0(Native Method) ~[?:?]
1/1 5:54:30 PM [Error] at java.base/java.lang.Class.forName(Class.java:534) ~[?:?]
1/1 5:54:30 PM [Error] at java.base/java.lang.Class.forName(Class.java:513) ~[?:?]
1/1 5:54:30 PM [Error] at io.papermc.reflectionrewriter.runtime.AbstractDefaultRulesReflectionProxy.forName(AbstractDefaultRulesReflectionProxy.java:68) ~[reflection-rewriter-runtime-0.0.3.jar:?]
1/1 5:54:30 PM [Error] at io.papermc.paper.pluginremap.reflect.PaperReflectionHolder.forName(Unknown Source) ~[paper-1.21.11.jar:1.21.11-39-e5e2c50]
1/1 5:54:30 PM [Error] at ImageFrame-1.9.0.0.jar//com.loohp.imageframe.nms.NMS.getInstance(NMS.java:37) ~[?:?]
1/1 5:54:30 PM [Error] at ImageFrame-1.9.0.0.jar//com.loohp.imageframe.invisibleframe.InvisibleFrameManager.withInvisibleItemFrameData(InvisibleFrameManager.java:130) ~[?:?]
1/1 5:54:30 PM [Error] at ImageFrame-1.9.0.0.jar//com.loohp.imageframe.invisibleframe.InvisibleFrameManager.addRecipes(InvisibleFrameManager.java:107) ~[?:?]
1/1 5:54:30 PM [Error] at ImageFrame-1.9.0.0.jar//com.loohp.imageframe.invisibleframe.InvisibleFrameManager.(InvisibleFrameManager.java:93) ~[?:?]
1/1 5:54:30 PM [Error] at ImageFrame-1.9.0.0.jar//com.loohp.imageframe.ImageFrame.onEnable(ImageFrame.java:279) ~[?:?]
1/1 5:54:30 PM [Error] at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:279) ~[paper-api-1.21.11-R0.1-SNAPSHOT.jar:?]
1/1 5:54:30 PM [Error] at io.papermc.paper.plugin.manager.PaperPluginInstanceManager.enablePlugin(PaperPluginInstanceManager.java:202) ~[paper-1.21.11.jar:1.21.11-39-e5e2c50]
1/1 5:54:30 PM [Error] at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.enablePlugin(PaperPluginManagerImpl.java:109) ~[paper-1.21.11.jar:1.21.11-39-e5e2c50]
1/1 5:54:30 PM [Error] at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:520) ~[paper-api-1.21.11-R0.1-SNAPSHOT.jar:?]
1/1 5:54:30 PM [Error] at org.bukkit.craftbukkit.CraftServer.enablePlugin(CraftServer.java:639) ~[paper-1.21.11.jar:1.21.11-39-e5e2c50]
1/1 5:54:30 PM [Error] at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:596) ~[paper-1.21.11.jar:1.21.11-39-e5e2c50]
1/1 5:54:30 PM [Error] at net.minecraft.server.MinecraftServer.initPostWorld(MinecraftServer.java:636) ~[paper-1.21.11.jar:1.21.11-39-e5e2c50]
1/1 5:54:30 PM [Error] at net.minecraft.server.dedicated.DedicatedServer.initServer(DedicatedServer.java:365) ~[paper-1.21.11.jar:1.21.11-39-e5e2c50]
1/1 5:54:30 PM [Error] at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1260) ~[paper-1.21.11.jar:1.21.11-39-e5e2c50]
1/1 5:54:30 PM [Error] at net.minecraft.server.MinecraftServer.lambda$spin$2(MinecraftServer.java:388) ~[paper-1.21.11.jar:1.21.11-39-e5e2c50]
1/1 5:54:30 PM [Error] at java.base/java.lang.Thread.run(Thread.java:1583) ~[?:?]
1/1 5:54:30 PM [Error] Caused by: java.lang.ClassNotFoundException: org.bukkit.craftbukkit.v1_21_R7.inventory.CraftItemStack
1/1 5:54:30 PM [Error] at org.bukkit.plugin.java.PluginClassLoader.loadClass0(PluginClassLoader.java:208) ~[paper-api-1.21.11-R0.1-SNAPSHOT.jar:?]
1/1 5:54:30 PM [Error] at org.bukkit.plugin.java.PluginClassLoader.loadClass(PluginClassLoader.java:175) ~[paper-api-1.21.11-R0.1-SNAPSHOT.jar:?]
1/1 5:54:30 PM [Error] at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) ~[?:?]
1/1 5:54:30 PM [Error] ... 21 more
1/1 5:54:30 PM [Info] [ImageFrame] Disabling ImageFrame v1.9.0.0
1/1 5:54:30 PM [Info] [01:54:30 INFO]: [ImageFrame] ImageFrame has been Disabled!
1/1 5:54:30 PM [Info] [SimpleMoreSounds] Enabling SimpleMoreSounds v3.0
1/1 5:54:30 PM [Info] [SimpleMoreSounds] SimpleMoreSounds plugin successfully enabled!
1/1 5:54:30 PM [Info] [voicechat] Enabling voicechat v2.6.7
1/1 5:54:30 PM [Info] [voicechat] Initializing compatibility for version 1.21.11-R0.1
1/1 5:54:30 PM [Info] [voicechat] Compatibility version 20
1/1 5:54:30 PM [Info] [voicechat] Successfully initialized commodore command completion
1/1 5:54:30 PM [Info] [InstantRestock] Enabling InstantRestock v2.6.1
1/1 5:54:31 PM [Info] [InstantRestock] Enabled InstantRestock!
1/1 5:54:31 PM [Info] [NotBounties] Enabling NotBounties v1.22.26
1/1 5:54:32 PM [Info] [Craftable] Enabling Craftable v1.3
1/1 5:54:32 PM [Info] [Craftable] Craftable plugin enabled!
1/1 5:54:32 PM [Info] [AxGraves] Enabling AxGraves v1.25.0
1/1 5:54:33 PM [Info] [spark] Starting background profiler...
1/1 5:54:33 PM [Info] Starting GS4 status listener
1/1 5:54:33 PM [Info] Thread Query Listener started
1/1 5:54:33 PM [Info] Query running on 0.0.0.0:23016
1/1 5:54:33 PM [Info] Running delayed init tasks
1/1 5:54:33 PM [Info] Done (16.997s)! For help, type "help"
1/1 5:54:33 PM [Info] [voicechat] Loading plugins
1/1 5:54:33 PM [Info] [voicechat] Loaded 0 plugin(s)
1/1 5:54:33 PM [Info] [01:54:33 INFO]: [voicechat] Initializing plugins
1/1 5:54:33 PM [Info] [01:54:33 INFO]: [voicechat] Initialized 0 plugin(s)
1/1 5:54:33 PM [Info] [voicechat] Using server-ip as bind address: 0.0.0.0
1/1 5:54:33 PM [Info] [voicechat] Voice chat server started at 0.0.0.0:27090

Here is the log when I am starting the server and the bolded+italic lines are the problems I see in the logs.
Also to add onto this, whenever I try to use any of the commands from the plugin it doesn't allow me to use it and says in red text in chat "An internal error occured while attempting to tab-complete this command"