Thank you for answering. I tried your suggestion, but it didn't work either. I think there's something wrong with my ELK, but I don't know what it can be. Here is the logstash:
[2018-11-27T08:35:56,309][WARN ][logstash.config.source.multilocal] Ignoring the 'pipelines.yml' file because modules or command line options are specified
[2018-11-27T08:35:56,400][INFO ][logstash.runner ] Starting Logstash {"logstash.version"=>"6.4.2"}
[2018-11-27T08:35:57,935][INFO ][logstash.pipeline ] Starting pipeline {:pipeline_id=>"main", "pipeline.workers"=>8, "pipeline.batch.size"=>125, "pipeline.batch.delay"=>50}
[2018-11-27T08:35:58,105][INFO ][logstash.outputs.elasticsearch] Elasticsearch pool URLs updated {:changes=>{:removed=>, :added=>[http://127.0.0.1:9200/]}}
[2018-11-27T08:35:58,106][INFO ][logstash.outputs.elasticsearch] Running health check to see if an Elasticsearch connection is working {:healthcheck_url=>http://127.0.0.1:9200/, :path=>"/"}
[2018-11-27T08:35:58,177][WARN ][logstash.outputs.elasticsearch] Restored connection to ES instance {:url=>"http://127.0.0.1:9200/"}
[2018-11-27T08:35:58,214][INFO ][logstash.outputs.elasticsearch] ES Output version determined {:es_version=>6}
[2018-11-27T08:35:58,214][WARN ][logstash.outputs.elasticsearch] Detected a 6.x and above cluster: the type
event field won't be used to determine the document _type {:es_version=>6}
[2018-11-27T08:35:58,216][INFO ][logstash.outputs.elasticsearch] New Elasticsearch output {:class=>"LogStash::Outputs::ElasticSearch", :hosts=>["//127.0.0.1:9200"]}
[2018-11-27T08:35:58,217][INFO ][logstash.outputs.elasticsearch] Using mapping template from {:path=>nil}
[2018-11-27T08:35:58,221][INFO ][logstash.outputs.elasticsearch] Elasticsearch pool URLs updated {:changes=>{:removed=>, :added=>[http://127.0.0.1:9200/]}}
[2018-11-27T08:35:58,222][INFO ][logstash.outputs.elasticsearch] Running health check to see if an Elasticsearch connection is working {:healthcheck_url=>http://127.0.0.1:9200/, :path=>"/"}
[2018-11-27T08:35:58,222][INFO ][logstash.outputs.elasticsearch] Attempting to install template {:manage_template=>{"template"=>"logstash-", "version"=>60001, "settings"=>{"index.refresh_interval"=>"5s"}, "mappings"=>{"default"=>{"dynamic_templates"=>[{"message_field"=>{"path_match"=>"message", "match_mapping_type"=>"string", "mapping"=>{"type"=>"text", "norms"=>false}}}, {"string_fields"=>{"match"=>"", "match_mapping_type"=>"string", "mapping"=>{"type"=>"text", "norms"=>false, "fields"=>{"keyword"=>{"type"=>"keyword", "ignore_above"=>256}}}}}], "properties"=>{"@timestamp"=>{"type"=>"date"}, "@version"=>{"type"=>"keyword"}, "geoip"=>{"dynamic"=>true, "properties"=>{"ip"=>{"type"=>"ip"}, "location"=>{"type"=>"geo_point"}, "latitude"=>{"type"=>"half_float"}, "longitude"=>{"type"=>"half_float"}}}}}}}}
[2018-11-27T08:35:58,228][WARN ][logstash.outputs.elasticsearch] Restored connection to ES instance {:url=>"http://127.0.0.1:9200/"}
[2018-11-27T08:35:58,245][INFO ][logstash.outputs.elasticsearch] ES Output version determined {:es_version=>6}
[2018-11-27T08:35:58,245][WARN ][logstash.outputs.elasticsearch] Detected a 6.x and above cluster: the type
event field won't be used to determine the document _type {:es_version=>6}
[2018-11-27T08:35:58,247][INFO ][logstash.outputs.elasticsearch] New Elasticsearch output {:class=>"LogStash::Outputs::ElasticSearch", :hosts=>["//127.0.0.1:9200"]}
[2018-11-27T08:35:58,247][INFO ][logstash.outputs.elasticsearch] Using mapping template from {:path=>nil}
[2018-11-27T08:35:58,249][INFO ][logstash.outputs.elasticsearch] Attempting to install template {:manage_template=>{"template"=>"logstash-", "version"=>60001, "settings"=>{"index.refresh_interval"=>"5s"}, "mappings"=>{"default"=>{"dynamic_templates"=>[{"message_field"=>{"path_match"=>"message", "match_mapping_type"=>"string", "mapping"=>{"type"=>"text", "norms"=>false}}}, {"string_fields"=>{"match"=>"", "match_mapping_type"=>"string", "mapping"=>{"type"=>"text", "norms"=>false, "fields"=>{"keyword"=>{"type"=>"keyword", "ignore_above"=>256}}}}}], "properties"=>{"@timestamp"=>{"type"=>"date"}, "@version"=>{"type"=>"keyword"}, "geoip"=>{"dynamic"=>true, "properties"=>{"ip"=>{"type"=>"ip"}, "location"=>{"type"=>"geo_point"}, "latitude"=>{"type"=>"half_float"}, "longitude"=>{"type"=>"half_float"}}}}}}}}
[2018-11-27T08:35:59,759][INFO ][filewatch.observingtail ] START, creating Discoverer, Watch with file and sincedb collections
[2018-11-27T08:35:59,759][INFO ][filewatch.observingtail ] START, creating Discoverer, Watch with file and sincedb collections
[2018-11-27T08:35:59,760][INFO ][logstash.pipeline ] Pipeline started successfully {:pipeline_id=>"main", :thread=>"#<Thread:0x546e06b8@C:/Bitnami/elk/logstash/logstash-core/lib/logstash/pipeline.rb:157 sleep>"}
[2018-11-27T08:35:59,774][INFO ][logstash.agent ] Pipelines running {:count=>1, :running_pipelines=>[:main], :non_running_pipelines=>}
[2018-11-27T08:35:59,869][INFO ][logstash.agent ] Successfully started Logstash API endpoint {:port=>9600}