My Cloud PR4100 / EX2 Ultra Login My Cloud OS5 504 Error

A 504 Gateway Timeout error when logging into your My Cloud PR4100 or EX2 Ultra running My Cloud OS 5 usually means the device or its services are failing to communicate properly with WD's cloud servers. Here’s how to troubleshoot and fix it:

✅ Quick Explanation of 504 Error

The 504 Gateway Timeout typically indicates that:

The My Cloud device is unable to connect to the internet properly.

WD's remote servers are unresponsive.

Port forwarding or firewall settings are blocking communication.

Device services (like Cloud Access) are stuck or crashed.

🔧 Step-by-Step Fixes

1. Restart the Device and Router

Power off the My Cloud device.

Power off your router.

Wait 30 seconds, then power on the router, followed by the My Cloud.

Try logging in again via OS5 Dashboard or cloud login.

2. Check Cloud Access Status

Login to the local dashboard:

URL: http://<device-IP> or http://mycloudpr4100.local

Go to: Settings > Cloud Access

Check if it says Connected or Relay Connection Established

If it's stuck or disconnected, toggle Cloud Access off and back on

3. Update the Firmware

Go to the local dashboard and:

Navigate to Settings > Firmware Update

Select Auto Update or manually update using the WD support page:

https://support.wdc.com/downloads.aspx

4. Manually Set DNS

Sometimes DNS resolution fails, causing timeouts.

Go to Settings > Network

Set DNS to:

Primary DNS: 8.8.8.8 (Google)

Secondary DNS: 1.1.1.1 (Cloudflare)

Save and reboot the device.

5. Check Port Forwarding (If Using Cloud Access)

WD OS5 cloud features need ports 443 and 80:

Make sure these ports are open on your router.

You can enable UPnP or manually forward:

External Port 443 → Internal Port 443

External Port 80 → Internal Port 80

6. Factory Restore (As Last Resort)

If the issue persists and you can’t access even locally:

Backup data (if accessible).

Do a System Only Restore via reset button:

Hold reset button (back panel) for 40 seconds (with power on).

This resets system settings but does not erase data.

🔍 Optional: Check WD Server Status

Go to: https://status.mycloud.com/

To see if WD's remote services are down.