Error changing the selected API - wazuh-dashboard

[Denis Grilli]

Hi all, 

My installation of wazuh includes 2 indexer server and 4 wazuh manager servers.
Dashboard is installed on the wazuh indexer server and it used to work fine.

Recently, when I try to switch the API server (top right corner) between wazuh manager servers I got the following error:

Error changing the selected API
Error: 1000 - Unexpected error at ApiCheck.returnErrorInstance (https://wazuh-dashboard.gmsl.gasops.co.uk/414303/bundles/plugin/wazuh/wazuh.plugin.js:1:553660) at ApiCheck.checkApi (https://wazuh-dashboard.gmsl.gasops.co.uk/414303/bundles/plugin/wazuh/wazuh.plugin.js:1:553372) at async https://wazuh-dashboard.gmsl.gasops.co.uk/414303/bundles/plugin/wazuh/wazuh.chunk.2.js:1:3302099
Only 1 of the 4th wazuh manager server works, anyone can suggest how to troubleshoot this? I couldn't find any obvious error in the indexer / dashboard except for the one above.

Thanks in advance 

[Federico Gustavo Caffieri]

It would help to understand your environment a bit better and gather some diagnostic info in order to help you.

- Which of the 4 manager servers is the one that works? Is it your cluster master node?
- Did anything change recently in your environment — updates, certificate renewals, network/firewall changes, or did you re-add the API entries manually?
- Are the 4 API entries in the dashboard (Mennu > Settings > API) pointing to each manager's individual IP/hostname, or through a load balancer?

Execute these commands on each of the failing manager nodes:

- Check if the Wazuh manager and API are running:
```
systemctl status wazuh-manager
```

- Check if the API is actually listening on port 55000:
```
ss -tlnp | grep 55000
```

- Test the API directly from the dashboard server (replace with each manager's IP):
```
curl -k -X GET "https://<MANAGER_IP>:55000/" \
  -u <USER>:<PASSWORD>
```

- Check the API log for errors on the failing nodes:
```
tail -100 /var/ossec/logs/api.log
```

One thing to check in the meantime:

If the working API entry is your cluster master node, that may be expected behavior — the Wazuh API sits on the master node, and certain cluster-wide operations can only be served from there. Worker nodes do run their own API, but depending on your Wazuh version and how the dashboard plugin handles multi-API setups, connecting directly to a worker may fail for specific checks.
You can check these [discussions](https://github.com/wazuh/wazuh/discussions/14192)

[Denis Grilli]

Thanks for your reply.

My setup is using wazuh 4.14.3 and is formed by
two indexer node in a cluster

4 manager nodes in a cluster

dashboard installed in the indexer nodes

And you are right the only worker node is the master one 

workerX:~# /var/ossec/bin/cluster_control -l
NAME      TYPE    VERSION  ADDRESS
worker1     master  4.14.3 
worker2   worker  4.14.3   
worker3  worker  4.14.3   
worker4   worker  4.14.3

All the test you suggested are successfully so I can connect to any worker on port 55000 correctly. The api log reports only one line when I try to switch node in the dashboard:

2026/02/23 15:38:55 INFO: wazuh-wui <worker2 ip> "GET /manager/info" with parameters {} and body {} done in 0.061s: 200

The error is showing when I am in the overview page (and trying to switch node) but also when I go to the Server APIs page (under Dashboard management section) where it shows the correct API version installed but cannot check if an update is required.

I am sure it was working before but not sure when it stopped (probably after an update).

Please, let me know if you have any other check I can do to provide more information.