---
title: "How to fix Microsoft event ID 5840? Domain controller warnings due to Microsoft changes to Netlogon"
canonical: "https://www.techtime-initiative.com/space/EasySSO/3244554/How%20to%20fix%20Microsoft%20event%20ID%205840%3F%20Domain%20controller%20warnings%20due%20to%20Microsoft%20changes%20to%20Netlogon"
format: markdown
---
Upgrade to Jespa version 2.0.1 or later.

Versions before Jespa version 2.0.1 do not fully support "Secure RPC" for Netlogon, which produces an error log in Domain controllers due to a recent update tied to [CVE-2022-38023](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-38023). Since April 2023, by default, this leads to EasySSO no longer working.

The event you may see in your Domain Controller event logs:

```
5840 The Netlogon service created a secure channel with a client with RC4.
```

For EasySSO, we use the IOPLEX Jespa library to perform NTLM and Kerberos authentication.

## Steps to get things sorted

> ℹ️ IOPLEX has said that version 2.x will work with "license keys purchased within the last 4 years, from approximately December of 2018". If you might have an older license, please contact us, and we will request a new one before upgrading Jespa

- Verify that your Jespa license was delivered after December 2018.
- Verify you are using EasySSO v4.8.9 or later
- Download Jespa version 2.0.1 or newer from [https://www.ioplex.com/downloads.php](https://www.ioplex.com/downloads.php)
- Upload the new Jespa version into the EasySSO/NTLM/IOPLEX Jespa licensing tab
- Go to the UPM and disable EasySSO
- Re-enable EasySSO to force the Java Virtual Machine to reload the library (especially if the system is under load)