Initial Steps

• [yes] I have updated to the latest build from Jenkins before reporting a bug
• [yes] I have checked, if the bug was not already reported by using the search.
• [yes] Attached is my ForgeEssentials/modlist.txt, my latest.log, and my debug.log
• [yes] Also, attached are the client logs (if applicable)

Describe the bug
During the starting process server, I encountered some errors from ForgeEssentials related to Mixing.
Example :

[22:42:05] [main/WARN] [mixin]: Mixin apply failed mixins.forgeessentials.json:command.MixinICommandSender -> net.minecraft.network.rcon.RConConsoleSource: org.spongepowered.asm.mixin.transformer.throwables.InvalidMixinException Mixin mixins.forgeessentials.json:command.MixinICommandSender contains non-private static field launchLog:Lorg/apache/logging/log4j/Logger; org.spongepowered.asm.mixin.transformer.throwables.InvalidMixinException: Mixin mixins.forgeessentials.json:command.MixinICommandSender contains non-private static field launchLog:Lorg/apache/logging/log4j/Logger; at org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.validateField(MixinPreProcessorStandard.java:686) ~[forgeessentials-1.12.2-12.3.90-server.jar:?] at org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.attachFields(MixinPreProcessorStandard.java:595) ~[forgeessentials-1.12.2-12.3.90-server.jar:?] at org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.attach(MixinPreProcessorStandard.java:292) ~[forgeessentials-1.12.2-12.3.90-server.jar:?] at org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.createContextFor(MixinPreProcessorStandard.java:267) ~[forgeessentials-1.12.2-12.3.90-server.jar:?] at org.spongepowered.asm.mixin.transformer.MixinInfo.createContextFor(MixinInfo.java:1271) ~[forgeessentials-1.12.2-12.3.90-server.jar:?] at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.apply(MixinApplicatorStandard.java:287) ~[forgeessentials-1.12.2-12.3.90-server.jar:?] at org.spongepowered.asm.mixin.transformer.TargetClassContext.applyMixins(TargetClassContext.java:345) ~[forgeessentials-1.12.2-12.3.90-server.jar:?] at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:569) [forgeessentials-1.12.2-12.3.90-server.jar:?] at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:351) [forgeessentials-1.12.2-12.3.90-server.jar:?] at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:208) [forgeessentials-1.12.2-12.3.90-server.jar:?] at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClassBytes(MixinTransformer.java:178) [forgeessentials-1.12.2-12.3.90-server.jar:?] at org.spongepowered.asm.mixin.transformer.Proxy.transform(Proxy.java:72) [forgeessentials-1.12.2-12.3.90-server.jar:?] at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:279) [launchwrapper-1.12.jar:?] at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:176) [launchwrapper-1.12.jar:?] at java.lang.ClassLoader.loadClass(ClassLoader.java:418) [?:1.8.0_282] at java.lang.ClassLoader.loadClass(ClassLoader.java:351) [?:1.8.0_282] at net.minecraft.server.dedicated.DedicatedServer.<init>(DedicatedServer.java:58) [nz.class:?] at net.minecraft.server.MinecraftServer.main(MinecraftServer.java:1542) [MinecraftServer.class:?] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_282] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_282] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_282] at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_282] at net.minecraft.launchwrapper.Launch.launch(Launch.java:135) [launchwrapper-1.12.jar:?] at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.12.jar:?] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_282] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_282] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_282] at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_282] at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.run(ServerLaunchWrapper.java:70) [server.jar:?] at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:34) [server.jar:?]
To Reproduce
Steps to reproduce the behavior:

1. Download build version 90 of ForgeEssentials.
2. Put mod on server.
3. Start server.
4. See error in console.

Expected behavior
Server should start without errors but just some light warnings from ForgeEssentials.
Screenshots

• x
  Desktop (please complete the following information):
• OS: [Windows 10 Pro]
• Browser [Google Chrome]
• Version [Chrome's version 91]
• Version [ForgeEssentials 1.12.2 build-90]
  latest.log
  modlist.txt

Additional context

• x

Good catch, I will take a look. This doesn't cause a huge issue cause it is only the Rcon that is not getting injected.