When loading:

[09:33:38 INFO]: [dynmap] Loading server plugin dynmap v3.7-SNAPSHOT-968
[09:33:38 INFO]: [dynmap] version=1.21.10-84-bac3da1 (MC: 1.21.10)
[09:33:38 ERROR]: [dynmap] Cannot find [Lnet.minecraft.server.BiomeBase;
[09:33:38 ERROR]: [dynmap] Cannot find net.minecraft.server.BiomeStorage
[09:33:38 ERROR]: [dynmap] Unable to find method getHandle for org.bukkit.craftbukkit.CraftChunk
[09:33:38 ERROR]: [dynmap] Unable to find method getProperties for com.mojang.authlib.GameProfile
[09:33:38 ERROR]: [dynmap] Unable to find method getValue for com.mojang.authlib.properties.Property
[09:33:38 ERROR]: [dynmap] Error loading org.dynmap.bukkit.helper.BukkitVersionHelperCB
java.lang.reflect.InvocationTargetException: null
        at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:74) ~[?:?]
        at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499) ~[?:?]
        at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:483) ~[?:?]
        at Dynmap-3.7-beta-8-spigot (1).jar/org.dynmap.bukkit.Helper.loadVersionHelper(Helper.java:15) ~[Dynmap-3.7-beta-8-spigot (1).jar:?]
        at Dynmap-3.7-beta-8-spigot (1).jar/org.dynmap.bukkit.Helper.getHelper(Helper.java:109) ~[Dynmap-3.7-beta-8-spigot (1).jar:?]
        at Dynmap-3.7-beta-8-spigot (1).jar/org.dynmap.bukkit.DynmapPlugin.onLoad(DynmapPlugin.java:900) ~[Dynmap-3.7-beta-8-spigot (1).jar:?]
        at io.papermc.paper.plugin.storage.ServerPluginProviderStorage.processProvided(ServerPluginProviderStorage.java:59) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at io.papermc.paper.plugin.storage.ServerPluginProviderStorage.processProvided(ServerPluginProviderStorage.java:18) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at io.papermc.paper.plugin.storage.SimpleProviderStorage.enter(SimpleProviderStorage.java:39) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler.enter(LaunchEntryPointHandler.java:39) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at org.bukkit.craftbukkit.CraftServer.loadPlugins(CraftServer.java:555) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at net.minecraft.server.dedicated.DedicatedServer.initServer(DedicatedServer.java:323) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1262) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at net.minecraft.server.MinecraftServer.lambda$spin$2(MinecraftServer.java:383) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at java.base/java.lang.Thread.run(Thread.java:1447) ~[?:?]
Caused by: java.lang.IllegalArgumentException: Error initializing dynmap - bukkit version incompatible!
        at Dynmap-3.7-beta-8-spigot (1).jar/org.dynmap.bukkit.helper.BukkitVersionHelperGeneric.<init>(BukkitVersionHelperGeneric.java:166) ~[Dynmap-3.7-beta-8-spigot (1).jar:?]
        at Dynmap-3.7-beta-8-spigot (1).jar/org.dynmap.bukkit.helper.BukkitVersionHelperCB.<init>(BukkitVersionHelperCB.java:44) ~[Dynmap-3.7-beta-8-spigot (1).jar:?]
        at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:62) ~[?:?]
        ... 14 more
[09:33:38 INFO]: [dynmap] Mod Support API available

When enabling:

[09:33:43 INFO]: [dynmap] Enabling dynmap v3.7-SNAPSHOT-968
[09:33:43 INFO]: [dynmap] Dynmap is disabled (unsupported platform)
[09:33:43 ERROR]: Error occurred while enabling dynmap v3.7-SNAPSHOT-968 (Is it up to date?)
java.lang.NullPointerException: Cannot invoke "org.dynmap.DynmapCore.disableCore()" because "this.core" is null
        at Dynmap-3.7-beta-8-spigot (1).jar/org.dynmap.bukkit.DynmapPlugin.onDisable(DynmapPlugin.java:1094) ~[Dynmap-3.7-beta-8-spigot (1).jar:?]
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:285) ~[paper-api-1.21.10-R0.1-SNAPSHOT.jar:?]
        at Dynmap-3.7-beta-8-spigot (1).jar/org.dynmap.bukkit.DynmapPlugin.onEnable(DynmapPlugin.java:916) ~[Dynmap-3.7-beta-8-spigot (1).jar:?]
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:279) ~[paper-api-1.21.10-R0.1-SNAPSHOT.jar:?]
        at io.papermc.paper.plugin.manager.PaperPluginInstanceManager.enablePlugin(PaperPluginInstanceManager.java:202) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.enablePlugin(PaperPluginManagerImpl.java:109) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:520) ~[paper-api-1.21.10-R0.1-SNAPSHOT.jar:?]
        at org.bukkit.craftbukkit.CraftServer.enablePlugin(CraftServer.java:640) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:596) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at net.minecraft.server.MinecraftServer.initPostWorld(MinecraftServer.java:636) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at net.minecraft.server.dedicated.DedicatedServer.initServer(DedicatedServer.java:368) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1262) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at net.minecraft.server.MinecraftServer.lambda$spin$2(MinecraftServer.java:383) ~[paper-1.21.10.jar:1.21.10-84-bac3da1]
        at java.base/java.lang.Thread.run(Thread.java:1447) ~[?:?]