Plugin is crashing with geyser

[romulog2silva]

[09:55:45 INFO]: [FastLogin] Enabling FastLogin v1.12-SNAPSHOT-65a379c
[09:55:46 ERROR]: Error occurred while enabling FastLogin v1.12-SNAPSHOT-65a379c (Is it up to date?)
java.lang.NoSuchMethodError: 'org.geysermc.geyser.configuration.GeyserConfiguration org.geysermc.geyser.GeyserImpl.getConfig()'
at com.github.games647.fastlogin.core.hooks.bedrock.GeyserService.(GeyserService.java:46) ~[FastLoginBukkit(7).jar:?]
at com.github.games647.fastlogin.bukkit.FastLoginBukkit.initializeFloodgate(FastLoginBukkit.java:164) ~[FastLoginBukkit(7).jar:?]
at com.github.games647.fastlogin.bukkit.FastLoginBukkit.onEnable(FastLoginBukkit.java:104) ~[FastLoginBukkit(7).jar:?]
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:281) ~[pufferfish-api-1.20.1-R0.1-SNAPSHOT.jar:?]
at io.papermc.paper.plugin.manager.PaperPluginInstanceManager.enablePlugin(PaperPluginInstanceManager.java:189) ~[pufferfish-1.20.1.jar:git-Pufferfish-27]
at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.enablePlugin(PaperPluginManagerImpl.java:104) ~[pufferfish-1.20.1.jar:git-Pufferfish-27]
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:507) ~[pufferfish-api-1.20.1-R0.1-SNAPSHOT.jar:?]
at org.bukkit.craftbukkit.v1_20_R1.CraftServer.enablePlugin(CraftServer.java:642) ~[pufferfish-1.20.1.jar:git-Pufferfish-27]
at org.bukkit.craftbukkit.v1_20_R1.CraftServer.enablePlugins(CraftServer.java:553) ~[pufferfish-1.20.1.jar:git-Pufferfish-27]
at net.minecraft.server.MinecraftServer.loadWorld0(MinecraftServer.java:637) ~[pufferfish-1.20.1.jar:git-Pufferfish-27]
at net.minecraft.server.MinecraftServer.loadLevel(MinecraftServer.java:436) ~[pufferfish-1.20.1.jar:git-Pufferfish-27]
at net.minecraft.server.dedicated.DedicatedServer.initServer(DedicatedServer.java:310) ~[pufferfish-1.20.1.jar:git-Pufferfish-27]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1102) ~[pufferfish-1.20.1.jar:git-Pufferfish-27]
at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:319) ~[pufferfish-1.20.1.jar:git-Pufferfish-27]
at java.lang.Thread.run(Thread.java:1583) ~[?:?]
[09:55:46 INFO]: [FastLogin] Disabling FastLogin v1.12-SNAPSHOT-65a379c
[09:55:46 INFO]: [FastLogin] Safely shutting down scheduler. This could take up to one minute.

[Flpvoigt]

This is a binary compatibility problem between this FastLogin build and the installed Geyser version, not a configuration or Java-runtime error.

FastLogin 1.12-SNAPSHOT-65a379c was compiled against a Geyser API that exposed GeyserImpl.getConfig(). Geyser later changed that API, so the JVM can load the classes but cannot find the exact method FastLogin was compiled to call; that is why the result is NoSuchMethodError.

The same break is already tracked in issue #1342. The practical options are:

1. Use a newer FastLogin build that explicitly contains the Geyser compatibility fix, when one is available.
2. Temporarily use a Geyser version from before that API change, while considering the security/support trade-off of running an older build.
3. Remove/disable the Geyser integration until the compatibility issue is fixed.

Also check the plugins directory for duplicate FastLogin or Geyser JARs before restarting. Changing FastLogin's config or upgrading Java alone will not restore a method that no longer exists in the loaded Geyser API.