Logstash v1.5.2 crash

logstash plugin logstash was stopped due to a crash caused by the infinite. This workaround?

A plugin had an unrecoverable error. Will restart this plugin.
  Plugin: <LogStash::Inputs::File path=>["/usr1/s3/alpha/bz/*"], sincedb_path=>"/usr1/last-s3-file/alpha-bz-last-s3-file", start_position=>"beginning", delimiter=>"\n">
  Error: string not matched
  Exception: IndexError
  Stack: org/jruby/RubyString.java:3912:in `[]='
/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-1.5.2.2-java/lib/logstash/event.rb:73:in `initialize'
/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-codec-json-1.0.0/lib/logstash/codecs/json.rb:40:in `decode'
/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-input-file-1.0.0/lib/logstash/inputs/file.rb:138:in `run'
/opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.6.4/lib/filewatch/tail.rb:184:in `_read_file'
org/jruby/RubyArray.java:1613:in `each'
/opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.6.4/lib/filewatch/tail.rb:183:in `_read_file'
org/jruby/RubyKernel.java:1511:in `loop'
/opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.6.4/lib/filewatch/tail.rb:179:in `_read_file'
/opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.6.4/lib/filewatch/tail.rb:84:in `subscribe'
/opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.6.4/lib/filewatch/watch.rb:67:in `each'
org/jruby/RubyArray.java:1613:in `each'
/opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.6.4/lib/filewatch/watch.rb:64:in `each'
/opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.6.4/lib/filewatch/watch.rb:117:in `subscribe'
/opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.6.4/lib/filewatch/tail.rb:75:in `subscribe'
/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-input-file-1.0.0/lib/logstash/inputs/file.rb:136:in `run'
/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-1.5.2.2-java/lib/logstash/pipeline.rb:176:in `inputworker'
/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-1.5.2.2-java/lib/logstash/pipeline.rb:170:in `start_input' {:level=>:error, :file=>"logstash/pipeline.rb", :line=>"181", :method=>"inputworker"}