[15:40:06 INFO]: [PlayerAnimator] Enabling PlayerAnimator vR1.2.7
[15:40:06 ERROR]: Error occurred while enabling PlayerAnimator vR1.2.7 (Is it up to date?)
java.lang.IllegalStateException: Version not supported
at oraxen-1.179.0.jar/com.ticxo.playeranimator.PlayerAnimatorImpl.applyNMS(PlayerAnimatorImpl.java:78) ~[oraxen-1.179.0.jar:?]
at oraxen-1.179.0.jar/com.ticxo.playeranimator.PlayerAnimatorImpl.(PlayerAnimatorImpl.java:49) ~[oraxen-1.179.0.jar:?]
at oraxen-1.179.0.jar/com.ticxo.playeranimator.PlayerAnimatorImpl.initialize(PlayerAnimatorImpl.java:24) ~[oraxen-1.179.0.jar:?]
at oraxen-1.179.0.jar/com.ticxo.playeranimator.PlayerAnimatorPluginImpl.onEnable(PlayerAnimatorPluginImpl.java:11) ~[oraxen-1.179.0.jar:?]
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:288) ~[paper-api-1.21-R0.1-SNAPSHOT.jar:?]
at io.papermc.paper.plugin.manager.PaperPluginInstanceManager.enablePlugin(PaperPluginInstanceManager.java:202) ~[paper-1.21.jar:1.21-123-0a1be9a]
at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.enablePlugin(PaperPluginManagerImpl.java:109) ~[paper-1.21.jar:1.21-123-0a1be9a]
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:520) ~[paper-api-1.21-R0.1-SNAPSHOT.jar:?]
at org.bukkit.craftbukkit.CraftServer.enablePlugin(CraftServer.java:640) ~[paper-1.21.jar:1.21-123-0a1be9a]
at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:589) ~[paper-1.21.jar:1.21-123-0a1be9a]
at net.minecraft.server.MinecraftServer.loadWorld0(MinecraftServer.java:754) ~[paper-1.21.jar:1.21-123-0a1be9a]
at net.minecraft.server.MinecraftServer.loadLevel(MinecraftServer.java:516) ~[paper-1.21.jar:1.21-123-0a1be9a]
at net.minecraft.server.dedicated.DedicatedServer.initServer(DedicatedServer.java:329) ~[paper-1.21.jar:1.21-123-0a1be9a]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1215) ~[paper-1.21.jar:1.21-123-0a1be9a]
at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:330) ~[paper-1.21.jar:1.21-123-0a1be9a]
at java.base/java.lang.Thread.run(Thread.java:1570) ~[?:?]
[15:40:06 INFO]: [PlayerAnimator] Disabling PlayerAnimator vR1.2.7

On the Spigot Website says 1.21 ist tested in the latest build but it do not load...

The error you provided has nothing to do with ProtocolLib as far as I see it so I'm going to close this. Please contact the author(s) of PlayerAnimator with your issue.