# Inteface conversion in running time error of a custum beat **URL:** \ **Category:** Beats\ **Tags:** beats-development\ **Created:** [August 8, 2017, 7:58am UTC](https://discuss.elastic.co/t/inteface-conversion-in-running-time-error-of-a-custum-beat/96216 "2017-08-08T07:58:13Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![boubker\_elamri](https://avatars.discourse-cdn.com/v4/letter/b/df788c/32.png) [@boubker\_elamri](https://discuss.elastic.co/u/boubker_elamri)\ **Post date:** [August 8, 2017, 7:58am UTC](https://discuss.elastic.co/t/inteface-conversion-in-running-time-error-of-a-custum-beat/96216/1 "2017-08-08T07:58:14Z")
hi everyone, I'm working on a beat and I came across an error like this : 2017/08/08 07:46:39.505926 beat.go:267: INFO Home path: [/home/hp/src/github.com/bob96/hc34] Config path: [/home/hp/src/github.com/bob96/hc34] Data path: [/home/hp/src/github.com/bob96/hc34/data] Logs path: [/home/hp/src/github.com/bob96/hc34/logs] 2017/08/08 07:46:39.505957 beat.go:177: INFO Setup Beat: hc34; Version: 5.1.3 2017/08/08 07:46:39.506040 logp.go:219: INFO Metrics logging every 30s 2017/08/08 07:46:39.506086 output.go:167: INFO Loading template enabled. Reading template file: /home/hp/src/github.com/bob96/hc34/hc34.template.json 2017/08/08 07:46:39.506262 output.go:178: INFO Loading template enabled for Elasticsearch 2.x. Reading template file: /home/hp/src/github.com/bob96/hc34/hc34.template-es2x.json 2017/08/08 07:46:39.506655 client.go:120: INFO Elasticsearch url: [http://localhost:9200](http://localhost:9200) 2017/08/08 07:46:39.506691 outputs.go:106: INFO Activated elasticsearch as output plugin. 2017/08/08 07:46:39.506756 publish.go:291: INFO Publisher name: hp-HP-Pavilion-15-Notebook-PC 2017/08/08 07:46:39.507171 async.go:63: INFO Flush Interval set to: 1s 2017/08/08 07:46:39.507188 async.go:64: INFO Max Bulk Size set to: 50 2017/08/08 07:46:39.507793 beat.go:207: INFO hc34 start running. 2017/08/08 07:46:39.507926 hc34.go:98: INFO hc34 is running! Hit CTRL-C to stop it. 2017/08/08 07:46:39.529717 hc34.go:174: INFO Event sent 2017/08/08 07:46:39.529741 hc34.go:107: INFO Event sent 2017/08/08 07:46:40.516641 client.go:652: INFO Connected to Elasticsearch version 5.5.0 2017/08/08 07:46:40.516666 output.go:214: INFO Trying to load template for client: [http://localhost:9200](http://localhost:9200) 2017/08/08 07:46:40.518197 output.go:235: INFO Template already exists and will not be overwritten. panic: interface conversion: interface {} is nil, not string goroutine 39 [running]: [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/elasticsearch.eventBulkMeta](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/elasticsearch.eventBulkMeta)(0xbfc600, 0xc42018e800, 0x0, 0xc42045ee40, 0x0, 0x0, 0x0) /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/elasticsearch/client.go:317 +0x121 [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/elasticsearch.bulkEncodePublishRequest](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/elasticsearch.bulkEncodePublishRequest)(0x7f4e810a2440, 0xc4201980f8, 0xbfc600, 0xc42018e800, 0x0, 0xc4201a2380, 0x1, 0x32, 0xc42019a2f0, 0x147, ...) /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/elasticsearch/client.go:290 +0xd6 [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/elasticsearch.(\*Client](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/elasticsearch.(*Client)).PublishEvents(0xc4201be140, 0xc4201a2380, 0x1, 0x32, 0x0, 0x0, 0x0, 0x0, 0x0) /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/elasticsearch/client.go:235 +0x138 [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/mode/single.(\*Mode](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/mode/single.(*Mode)).PublishEvents.func1(0xc4201c6780) /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/mode/single/single.go:89 +0x7b [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/mode/single.(\*Mode](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/mode/single.(*Mode)).publish(0xc4201c6780, 0x0, 0x0, 0x7f4e8116de00, 0xc4201afb88, 0xc42046a000, 0x0) /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/mode/single/single.go:144 +0x290 [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/mode/single.(\*Mode](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/mode/single.(*Mode)).PublishEvents(0xc4201c6780, 0x0, 0x0, 0x0, 0xc4201a2380, 0x1, 0x32, 0x1, 0x1) /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/mode/single/single.go:99 +0x7d [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/elasticsearch.(\*elasticsearchOutput](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/elasticsearch.(*elasticsearchOutput)).BulkPublish(0xc42019a280, 0x0, 0x0, 0x0, 0xc4201a2380, 0x1, 0x32, 0xc42003ffbe, 0xc42003ff28) /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/outputs/elasticsearch/output.go:308 +0x79 [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher.(\*outputWorker](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher.(*outputWorker)).sendBulk(0xc4201903c0, 0xc42003fd38, 0xc4201a2380, 0x1, 0x32) /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher/output.go:112 +0x123 [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher.(\*outputWorker](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher.(*outputWorker)).onBulk(0xc4201903c0, 0xc42003fd38, 0xc4201a2380, 0x1, 0x32) /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher/output.go:88 +0x281 [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher.(\*outputWorker](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher.(*outputWorker)).onMessage(0xc4201903c0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xc4201a2380, 0x1, 0x32) /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher/output.go:70 +0x9a [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher.(\*messageWorker](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher.(*messageWorker)).onEvent(0xc4201903c0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xc4201a2380, 0x1, 0x32) /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher/worker.go:83 +0x74 [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher.(\*messageWorker](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher.(*messageWorker)).run(0xc4201903c0) /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher/worker.go:69 +0x290 created by [github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher.(\*messageWorker](http://github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher.(*messageWorker)).init /home/hp/src/github.com/bob96/hc34/vendor/github.com/elastic/beats/libbeat/publisher/worker.go:57 +0x107 can someone help me please best regards! ---
**Author:** ![steffens](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/steffens/32/79630_2.png) [@steffens](https://discuss.elastic.co/u/steffens)\ **Post date:** [August 8, 2017, 12:39pm UTC](https://discuss.elastic.co/t/inteface-conversion-in-running-time-error-of-a-custum-beat/96216/2 "2017-08-08T12:39:03Z")
The line reported does not match any lines in 5.5 branch. Which commit ID are you using? Consider updating the vendored beats to most recent 5.5 or 5.6 commit. The closest possible issue with a potential matching panic is this line (5.4 branch): [https://github.com/elastic/beats/blob/5.4/libbeat/outputs/elasticsearch/client.go#L323](https://github.com/elastic/beats/blob/5.4/libbeat/outputs/elasticsearch/client.go#L323) This indicates the `event["type"]` field is missing. With most recent 5.5 branch, this field is not mandatory anymore. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [September 5, 2017, 12:39pm UTC](https://discuss.elastic.co/t/inteface-conversion-in-running-time-error-of-a-custum-beat/96216/3 "2017-09-05T12:39:05Z")
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