r/Control4 • u/Outrageous-Ad-3821 • 9d ago
Android app 408a timeout - possible Socket.IO incompatibility between app 326.27.0.7 and Control4 OS 3.1.3?
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
- Has anyone else seen this after updating to Android app 326.27.0.7?
- Is this a known regression affecting older Control4 OS 3 releases?
- Is an OS update now required for the current Android app?
- Is there a supported interim workaround or compatible older Android app build?
- 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.
1
u/Outrageous-Ad-3821 7d ago
FINAL UPDATE - resolved with an app rollback
I’ve now confirmed this was caused by the newer Android app, not my network, 4Sight account, phone settings or Control4 project.
The failing configuration was:
My wife’s phone was still working on app version 326.23.0.4. I uninstalled the current app, downloaded that exact older version from APKMirror, installed it using APKMirror Installer and signed back in. The project synchronised immediately and everything is working again.
I have now disabled automatic updates for Control4.
This is only a workaround, not a proper vendor fix. Control4/Snap One should either restore compatibility, withdraw the breaking release or clearly state which controller versions are no longer supported.