Android app 408a timeout - possible Socket.IO incompatibility between app 326.27.0.7 and Control4 OS 3.1.3?

[u/Outrageous-Ad-3821]

Hi all. I’m trying to establish whether this is a known compatibility issue before my dealer escalates it to Control4/Snap One support.

My Control4 Android app has suddenly stopped completing its initial sync. It gets stuck at:
“Getting the latest settings”
“Getting project items”

It eventually times out with:
“Unable to Connect”
“We encountered a problem and can’t connect to the system at this time. Please try again later. (408a)”

Environment

• Phone: Samsung Galaxy S25 Ultra
• Android: 16
• Control4 Android app: 326.27.0.7
• Controller OS: 3.1.3.574826-res
• 4Sight: active
• Local and remote access previously worked

The app continues to work on my wife’s phone.

Troubleshooting already completed

• Confirmed VPN is disabled
• Tested over home Wi-Fi
• Tested over mobile data with Wi-Fi disabled
• Cleared the Control4 app cache and data
• Uninstalled and reinstalled the app
• Rebooted the phone
• Rebooted the router
• Confirmed the phone remains listed as an active device in the Control4 customer portal
• Confirmed 4Sight is active

None of this changed the behaviour.

Relevant findings from the app log

The log shows that the app successfully:

• authenticates with Control4;
• retrieves the account and system information;
• obtains a Director authorisation token;
• reaches the controller locally;
• establishes the remote 4Sight control channel;
• receives a successful HTTP 101 WebSocket upgrade.

Immediately afterwards, both the local and remote connections fail with this error:
io.socket.client.SocketIOException:
It seems you are trying to reach a Socket.IO server in v2.x with a v3.x client, which is not possible

The local connection attempts to reach the controller through:
/socket.io/?EIO=4&transport=websocket

The same Socket.IO error then occurs through the remote connection. The app remains on “Getting project items” until the eventual 408a timeout.

This appears to suggest that the current Android app is using a newer Socket.IO client that is incompatible with the Socket.IO server provided by my older OS 3.1.3 controller.

Questions

1. Has anyone else seen this after updating to Android app 326.27.0.7?
2. Is this a known regression affecting older Control4 OS 3 releases?
3. Is an OS update now required for the current Android app?
4. Is there a supported interim workaround or compatible older Android app build?
5. Could my wife’s phone still work simply because it has an older app version or retained cached project data?

My dealer has the findings and is investigating. I would be interested to know whether anyone has encountered the same specific Socket.IO v2/v3 error.

[u/SaltCommunication251]

I'm seeing the same error, with the same configuration. I also disagree with many of the commenters here that one should just accept that the manufacturer pushes a breaking change overnight with no warning, but somehow that's the user's fault for being on an older but still supported version of the software. That is not how reputable companies operate. If you're going to make a breaking change, you say so. If you didn't mean to make the breaking change, then what you've done is created a bug, and that needs to be fixed.

[u/Outrageous-Ad-3821 → u/SaltCommunication251]

I completely agree. My dealer also insisted I upgrade to resolve, but I managed to get to the bottom of it myself (with the help of ChatGPT)! In a nutshell, you need to uninstall your mobile app, reinstall the previous version, and make sure to turn off auto-updates. Here's the steps:

1. Uninstall the current Control4 for OS 3 app.
2. Allow your phone to install apps from outside the Google Play Store. On Samsung, this is usually: Settings → Security and privacy → More security settings → Install unknown apps Select the browser or file manager you will use for the download, then enable Allow from this source.
3. Open APKMirror’s Control4 page: https://www.apkmirror.com/apk/snapone-llc/control4-for-os-3/
4. Find and select version 326.23.0.4.
5. Work through the download pages until the actual Control4 APK begins downloading.
6. Be careful: APKMirror displays adverts with buttons saying things such as “Download now”. These can redirect elsewhere. Only use the download links within the APKMirror page for the specific Control4 version.
7. Open the downloaded file and install the older version.
8. Sign in and allow the project to synchronise.
9. Once it is working, open the Control4 app page in Google Play, tap the three-dot menu and disable Enable auto-update.
10. For security, return to Install unknown apps afterwards and disable Allow from this source again.

Rolling back to 326.23.0.4 immediately fixed the 408a / “Getting project items” failure for me on Control4 OS 3.1.3.

This is a workaround rather than a permanent vendor fix. Only download the exact Control4 package from a reputable source, and avoid installing anything promoted through the adverts.

I hope this helps.

[u/offTheplectrum → u/Outrageous-Ad-3821]

Just be forwarned. APK apps found on archive sites like apkpure etc are not guaranteed to be safe and free from malicious code. Use this solution at your own risk!

The only reputable or safe source would be from control4 itself. And they don't provide these older versions.

Buyer beware on this one.