I keep getting an errors for my modded server

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    Within Minecraft when loading into the server it tells me

    Internal Exception: io.netty.handler.codec.EncoderException: java.lang.NoSuchMethodError: 'void net.minecraft.class_2540.method_34062(java.util.Collection, java.util.function.BiConsumer)'


    and MCLOGS tells me [18:40:22] [Render thread/ERROR]: No data fixer registered for decorative_blocks:dummy


    Here is a link to the MCLOGS if anyone can help me

    Vanilla Client Log [#GvXlTrb]
    8901 lines | 1 error
    mclo.gs


    Thank you

    it contains connection attempts to another host, not an aternos server