# WARN in Lenses Logs “Could not retrieve connectors”

**URL:** <https://ask.lenses.io/t/warn-in-lenses-logs-could-not-retrieve-connectors/183>\
**Category:** Apache Kafka Connectors\
**Created:** [February 7, 2024, 1:06pm UTC](https://ask.lenses.io/t/warn-in-lenses-logs-could-not-retrieve-connectors/183 "2024-02-07T13:06:37Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Edward\_k](https://avatars.discourse-cdn.com/v4/letter/e/b5a626/32.png) [@Edward\_k](https://ask.lenses.io/u/Edward_k)\
**Post date:** [February 7, 2024, 1:06pm UTC](https://ask.lenses.io/t/warn-in-lenses-logs-could-not-retrieve-connectors/183/1 "2024-02-07T13:06:37Z")

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In the Lenses logs, there are prominent WARN messages regarding the connectors, indicating that it couldn’t find a class implementing the connector. What does this mean, and how can it be resolved? I’ve included a snippet of the error message, but it essentially repeats the same fields and displays the names of other connectors.

```auto
WARN [i.l.c.c.ConnectorWatcher$] [ioapp-compute-8] Could not retrieve connectors
io.lenses.core.connect.client.ConnectorError: Failed to find any class that implements Connector and which name matches 
org.apache.kafka.connect.file.FileStreamSourceConnector, available connectors are: 
PluginDesc{klass=class com.couchbase.connect.kafka.CouchbaseSinkConnector, 
name='com.couchbase.connect.kafka.CouchbaseSinkConnector', version='4.1.9', encodedVersion=4.1.9, type=sink, typeName='sink', 
location='file:/var/run/connect/connectors/third-party/kafka-connect-couchbase/'}, 
PluginDesc{klass=class com.couchbase.connect.kafka.CouchbaseSourceConnector, 
name='com.couchbase.connect.kafka.CouchbaseSourceConnector', version='4.1.9', encodedVersion=4.1.9, type=source, typeName='source', 
location='file:/var/run/connect/connectors/third-party/kafka-connect-couchbase/'}, 
PluginDesc{klass=class com.datamountaineer.streamreactor.connect.azure.documentdb.sink.DocumentDbSinkConnector, 
name='com.datamountaineer.streamreactor.connect.azure.documentdb.sink.DocumentDbSinkConnector', version='5.0.1'....

```

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<div class="post-metadata">

**Author:** ![grudtnerv](https://dub1.discourse-cdn.com/flex017/user_avatar/ask.lenses.io/grudtnerv/32/101_2.png) [@grudtnerv](https://ask.lenses.io/u/grudtnerv)\
**Post date:** [February 7, 2024, 1:08pm UTC](https://ask.lenses.io/t/warn-in-lenses-logs-could-not-retrieve-connectors/183/2 "2024-02-07T13:08:16Z")

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Hello Edward\_k,

This message indicates that you Kafka-connect attempted to find a class used in your connector but couldn’t find it. In this case, the class is: `org.apache.kafka.connect.file.FileStreamSourceConnector`. If you have multiple connectors activated in Lenses, this issue might go unnoticed. In such cases, you need to delete the problematic connector using the following command:

`curl -X DELETE http://kafka-connect.url:8083/connectors/<connector-name>`

Afterwards, recreate it, ensuring that the libraries used by the connector actually exist in your Kafka Connect installation and are also in the correct version.