Logstash json codec Failed to load class

Hey guys

i have a tcp output here and when i try to use a json* codec my logstash instance dies with error

LogStash::Json::GeneratorError: Failed to load class 'org.jruby.RubyObject$Access4JacksonDeserializer45931591': com.fasterxml.jackson.module.afterburner.ser.BeanPropertyAccessor

here is my config

input {
	stdin {}
	courier{
		port => 4546
		transport => "tls"
		ssl_certificate => "/root/log-courier.crt"
		ssl_key => "/root/log-courier.key"
	}
}

filter {    }

output {
	stdout { codec => rubydebug }

	tcp {
		mode => "client"
		host => "172.31.6.186"
		port => 4545
		codec => "json_lines"
	}    
}

Anyone know what's going on here ? thanks!