Came across this while building a stripped down echo server by pulling out just the mina and naggati parts from kestrel to familiarize myself with the system. After much toying and frustration, I realized the only difference was my mina version in ivy.xml, and sure enough after switching to M4 everything worked. I'm trying to figure it out, but I figured I'd log it here as well:

org.apache.mina.filter.codec.ProtocolDecoderException: java.lang.NoSuchFieldError: EMPTY_BUFFER (Hexdump: 77 0D 0A)

    at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecFilter.java:235)                                                    
    at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessa\

geReceived(DefaultIoFilterChain.java:434)

    at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:46)  

...