Sign In:     

Forum: VirtualDJ Technical Support

Topic: VDJ and Denon MCX8000 - Page: 2
Hello,

I am experiencing exactly the same issue with my Denon DJ MCX8000 and VirtualDJ 2026.

FX buttons 2 and 3 work normally.
FX button 1 does not activate, even if I change the assigned effect.

The FX1_PARAM knobs (left and right decks) are also not responding.

This problem appeared immediately after updating to VirtualDJ 2026.
I am using the default factory mapping, no custom scripts.
Clean Windows 11 installation, no SoundSwitch running.

It looks like FX slot 1 is not triggering correctly in this version.

Has anyone found a solution or identified a mapping change in 2026?

Thank you.
 
🔎 System Configuration

Computer: PC Windows
Operating System:
Windows 11 Home
Version 25H2
OS Build: 26200.7840

VirtualDJ:
Version 2026 (build b9005)

Controller: Denon MCX8000
Connected via direct USB (no hub)

Firmware versions (from Utility screen):

Engine Version: 0332

Display Version: Left 5170 / Right 5170

MCU Version: 2076

(All screenshots attached.)

🧩 Issue Description

Hello,

I am experiencing issues with my Denon MCX8000 on VirtualDJ 2026.

VirtualDJ starts correctly, the controller is properly detected in the Controllers tab, and audio works.

However, I have the following problems:

1️⃣ FX Issue

On both decks:

FX Button 1 → FLANGER STR → does NOT work

FX Button 2 → FILTER LP POS → works

FX Button 3 → FILTER HP POS → works

If I change the effect assigned to FX Button 1, it still does not respond.

This happens on both decks.

2️⃣ Startup behavior

Sometimes VirtualDJ has difficulty opening (launch behavior not always normal).

❓ Questions

Could this be related to:

Windows 11 version 25H2 (build 26200.7840)?

A compatibility issue with the latest Windows update?

A mapping issue?

A firmware interaction problem?

Has anyone tested MCX8000 successfully on Windows 11 25H2?

Thank you for your help.
 
🔎 System Configuration

Main Computer (problem machine):
Windows 11 Home
Version 25H2
OS Build: 26200.7840

VirtualDJ:
Version 2026 (build b9005)

Controller:
Denon MCX8000
Connected directly via USB (no hub)

Firmware versions:

Engine Version: 0332

Display Version: Left 5170 / Right 5170

MCU Version: 2076

(All screenshots attached.)

🧩 Background

The last full live use of this PC with the Denon MCX8000 was on New Year’s Eve 2025 during a professional event.
Everything was working perfectly at that time.

Recently, I started using it again to prepare DJ sets, and that is when I noticed the issue.

The problem appeared after updating to VirtualDJ 2026.

Between 31/12/2025 and today (26/02/2026), something must have changed:

A Windows update

A VirtualDJ update

Or another software-related modification

From my side, I did not intentionally change anything in my hardware setup or workflow.

🔧 Troubleshooting Already Performed

To try to fix the issue, I have:

Reinstalled VirtualDJ 2026

Rolled back to older 2025 builds

Completely reinstalled Windows

Reinstalled all drivers

Tested different USB configurations

Purchased and installed a new PCI USB card

Replaced the motherboard of the PC

This unfortunately resulted in significant additional costs.

Despite all of this, the problem remains.

🖥 Comparative Test

I tested the same Denon MCX8000 controller on another laptop running:

Windows 10

VirtualDJ 2026 (latest build)

On that system, everything works perfectly:

No FX issues

No crossfader/browser issues

So:

The controller is not defective

The firmware is correct

VirtualDJ 2026 works properly

The issue appears to be specific to my Windows 11 25H2 PC.

🎛 Issues Observed (Windows 11 PC Only)
1️⃣ FX Issue (both decks)

FX 1 → FLANGER STR → does NOT respond

FX 2 → FILTER LP POS → works

FX 3 → FILTER HP POS → works

Changing the assigned effect does not fix the issue.

2️⃣ Crossfader / Browser Issue (intermittent)

Occasionally, the crossfader moves the browser file list (track list) instead of only controlling audio.

This is very problematic during live DJ performance.

❓ Request

At this point, I cannot determine the root cause.

Could this be:

A compatibility issue with Windows 11 25H2 (build 26200.7840)?

A problematic Windows update?

A conflict with VirtualDJ 2026?

A configuration corruption despite full reinstallation?

This PC is my main professional performance machine (including video mixing), and I would like to continue using it, as it previously worked perfectly.

Any help or technical guidance would be greatly appreciated.

Thank you very much for your support.
 
Technical Question

Given the behavior observed, I am wondering whether a recent Windows 11 update (25H2 – build 26200.7840) may have modified something related to:

USB HID drivers

MIDI device handling

MIDI message interpretation

Device enumeration order

Or low-level USB communication

Since:

The controller works perfectly on Windows 10

The issue affects specific controls (FX 1 not responding)

The crossfader occasionally triggers browser scrolling (which suggests unexpected MIDI mapping behavior)

The problem persists even after reinstalling Windows

Could there be a change in how Windows 11 25H2 handles USB HID or MIDI devices that might interfere with VirtualDJ’s controller communication?

Is there anything specific I could check regarding:

HID driver versions

MIDI device priority

Hidden duplicate MIDI devices

Or registry-level device entries

Any guidance on deeper diagnostic steps would be greatly appreciated.
 
 
It appears that there is a generic MIDI issue with the latest Win 11 updates.
Please see .. https://www.virtualdj.com/wiki/Win11-KB5074105.html
If your last KB installed later than the one mentioned above in the Wiki, uniinstall them all up to the latest (so anything later than the KB5074105)

We have identfied the issue and reported to Microsoft. A fix will be rolled out soon i guess, but no ETA.
In the meantime, the method above ensures that your MIDI will work properly.
 
Hello Jimmy,

First of all, thank you very much for your reply by email and for the information regarding the Windows 11 Preview update KB5074105 (26200.7705). I really appreciate your support as part of the VirtualDJ team.

I would also like to thank DJ Dad, who took the time to step in on the VirtualDJ forum and help investigate the issue.

After many tests, it appears that the problems I experienced were likely related to this Windows update.

The symptoms were the following:

FX were not responding correctly on the MCX8000

Some effect knobs were inactive on both decks

At times, the crossfader caused abnormal behavior, including moving the file browser list without any intentional action

General unstable and inconsistent controller behavior

Before identifying the cause, I unfortunately explored several hardware possibilities, thinking it might be a USB or motherboard issue:

Installed a PCI USB expansion card

Performed various hardware checks

Eventually replaced the motherboard

In total, this cost me nearly €300 before realizing the issue was most likely software-related and connected to the Windows update.

As I was troubleshooting on my own, it was not easy to quickly identify the root cause.

In the end, I decided to:

Reinstall a stable previous version of Windows 11 (23H2)

Avoid the affected Preview version

Temporarily block problematic updates

After the clean reinstall, I also performed a full system optimization to ensure stability for professional DJ use:

Disabled automatic driver updates

Set the Windows Update service to manual and stopped

Switched to High Performance power mode

Disabled USB selective suspend

Disabled USB hub power saving

Adjusted ASIO latency to 256 samples in VirtualDJ

Disabled Windows system sounds

Since applying these changes, the MCX8000 is working perfectly with VirtualDJ.
FX are fully functional again, the crossfader behaves normally, and the system is stable and smooth.

I am sharing my experience in case it may help other users facing similar symptoms.

Thank you again to you, the VirtualDJ team, and the forum members for your help and support.

Kind regards,
Christophe
 
Hi, I'm also having MIDI problems, but with a Denon MC7000. The Select/Load knob only goes in one direction, downwards.