How to Fix the “fatal error in thread [main], exiting” When Deploying Easysearch

1. Problem Source

When deploying the latest version of Coco AI, the prerequisite Easysearch must be installed. The author used Easysearch 1.12.1 (2025‑04‑28). If Elasticsearch is already installed, Easysearch can be omitted.

If the plugin is not installed, the system runs without error. Installing the plugin via initialize.sh triggers the fatal error shown below.

java.lang.NoClassDefFoundError: org/easysearch/monitor/Rollup/RollupStatsAction

Full log is shown in the next section.

2. Problem Description

[2025-06-03T13:15:03.54, 037][INFO ][o.e.n.Node       ] [mytx-2025] node name [mytx-2025], node ID [7kgnlw9SEyTDw-tz8yAJ], cluster name [easysearch], roles [master, remote_cluster_client, data, ingest]
[2025-06-03T13:15:03.55, 226][ERROR][o.e.b.EasysearchuncaughtExceptionHandler] [mytx-2025] fatal error in thread [main], exiting
java.lang.NoClassDefFoundError: org/easysearch/monitor/Rollup/RollupStatsAction
    at org.easysearch.IndexManagementPlugin.<init>(IndexManagementPlugin.kt:521) ~[?:?]
    ... (stack trace omitted for brevity)
Caused by: java.lang.ClassNotFoundException: org.easysearch.monitor.Rollup.RollupStatsAction
    at java.net.URLClassLoader.findClass(URLClassLoader.java:445) ~[?:?]
    ... 17 more

The log indicates a NoClassDefFoundError for RollupStatsAction during initialization of the IndexManagementPlugin. Possible reasons include missing class files, mismatched dependency versions, incorrect classpath, corrupted JAR, or runtime incompatibility.

The author suspects this is a bug in the new version.

3. Temporary Workaround

Since the failure originates from the IndexManagementPlugin, the immediate fix is to remove that plugin.

3.1 Step 1: View the plugin list

3.2 Step 2: Remove the IndexManagement plugin

5. Summary

Ensure the system functions by uninstalling the problematic plugin, then verify operation.