## Connection errors

URL: https://docs.atlan.com/apps/connectors/database/ibm-db2-for-zos/troubleshooting/troubleshooting-ibm-db2-for-zos-connectivity

> Troubleshoot IBM Db2 for z/OS connection errors, including Db2 Connect license activation failures (ERRORCODE=-4230).

Use this guide to resolve errors that appear when Atlan connects to your Db2 for z/OS subsystem.

## Db2 Connect license invalid or not activated

> **Danger: Error**
>
> **The IBM Data Server for JDBC and SQLJ license was invalid or was not activated for the DB2 for z/OS subsystem. ERRORCODE=-4230, SQLSTATE=42968**

### Cause

Atlan connects with the IBM Db2 12.1 JDBC driver, which requires a Db2 Connect 12.1 license activated for your subsystem. The subsystem has no activated Db2 Connect license, or it was activated with an earlier kit, such as 11.5. This error appears only after the network connection succeeds, so it often surfaces right after you resolve firewall or DDF port issues.

### Solution

1. Download the Db2 Connect 12.1 license activation kit from IBM Passport Advantage.
2. Run the activation program from the kit against your subsystem. For Db2 Connect Unlimited Edition for System z, use the `db2connectactivate` utility.
3. Rerun **Test Authentication** in Atlan.

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## See also

[Set up IBM Db2 for z/OS](https://docs.atlan.com/llms/connectors/ibm-db2-for-zos/set-up-ibm-db2-for-zos/llms.txt): Review the Db2 Connect license and SSL prerequisites

## Need help

If you need assistance after trying these steps, contact Atlan support.

_Last updated: 14 October 2026._

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