按照老师的方法，但logstash启动失败，报错如下：
[ERROR][logstash.agent ] Failed to execute action {:action=>LogStash::PipelineAction::Create/pipeline_id:main, :exception=>“LogStash::ConfigurationError”, :message=>“Expected one of #, input, filter, output at line 1, column 1 (byte 1)”, :backtrace=>["/usr/local/elk/logstash/logstash-core/lib/logstash/compiler.rb:41:in compile_imperative'", "/usr/local/elk/logstash/logstash-core/lib/logstash/compiler.rb:49:incompile_graph’", “/usr/local/elk/logstash/logstash-core/lib/logstash/compiler.rb:11:in block in compile_sources'", "org/jruby/RubyArray.java:2577:inmap’”, “/usr/local/elk/logstash/logstash-core/lib/logstash/compiler.rb:10:in compile_sources'", "org/logstash/execution/AbstractPipelineExt.java:151:ininitialize’”, “org/logstash/execution/JavaBasePipelineExt.java:47:in initialize'", "/usr/local/elk/logstash/logstash-core/lib/logstash/java_pipeline.rb:24:ininitialize’”, “/usr/local/elk/logstash/logstash-core/lib/logstash/pipeline_action/create.rb:36:in execute'", "/usr/local/elk/logstash/logstash-core/lib/logstash/agent.rb:325:inblock in converge_state’”]}
[2019-08-25T18:55:26,366][INFO ][logstash.agent ] Successfully started Logstash API endpoint {:port=>9600}
[2019-08-25T18:55:31,481][INFO ][logstash.runner ] Logstash shut down.

请问老师如何解决呢？