The Companion App detects games through its driver service. The chain is:
Companion App → THGL Bridge Host (Windows service) → THGL Driver (kernel driver)
If any link is broken, the app cannot confirm that a supported game is running, so the game page keeps showing "Start the game to enable the overlay", the Open Overlay button stays disabled and the Session Log stays empty. Desktop mode still opens, but nothing is tracked.
Since version 16.2.1 the dashboard shows an amber banner at the top whenever this chain is broken, names the game that is running but cannot be tracked, and offers the fix:
- Start service - the THGL Bridge Host service is installed but stopped. Windows asks for administrator permission once, then the service starts and detection resumes within a few seconds.
- Restart service - the service runs but the kernel driver is not loaded, or the service does not answer. The service reinstalls and starts the driver every time it starts.
- Repair installation - the service is missing or it rejected the app's signature. This re-runs the installer, which re-registers the services and updates them.
The app also repairs a stopped service on its own when it runs with administrator rights.
The app is signed with a certificate issued by Certum. Its root certificate is not part of every Windows installation; Windows normally downloads it on demand. On stripped-down or offline Windows images that download never happens, the service cannot verify the app's signature and refuses it ("App signature rejected by the driver service").
The Bridge Host service shipped with the app since version 16.2.1 carries the Certum root itself and no longer depends on Windows for it. Repair installation installs that version. If you cannot update, install the certificate manually: run certutil -addstore -f Root <CertumTrustedNetworkCA2.cer> as administrator and reboot.
The driver only accepts app versions that are on an approval list, and the Bridge Host service keeps that list current by downloading it from th.gl. If a firewall or antivirus blocks the service, the list stays on an older version and the driver refuses every app update from then on - even though the app itself still reaches the internet and updates normally. Reinstalling does not help either: the installer does not carry the list, so a reinstall inherits the same outdated one.
Allow THGLBridgeHost.exe (in C:\Program Files\The Hidden Gaming Lair) through your security software. The service retries the download on its own every few minutes, and the banner disappears once it gets through. There is no button for this on purpose: restarting the service does not get past a block and takes the driver offline while it tries. Third-party firewalls do this more often than the Windows one; Bitdefender is one I have seen block it. In a debug snapshot, the Bridge Host log shows Failed to download manifest when this is the cause.
The same message also appears on machines where Windows Defender has been switched off by a "tweak" or "debloat" tool (Windows Security then says "managed by your organization" and "No active antivirus provider"). Those tools usually change more than Defender: root certificate updates and network rules the service depends on. The service runs as a system service, so it can be cut off even while your own programs reach the internet fine. Turn Defender back on and allow the app when asked; the service picks up the list on its next retry.
A related message, "Driver cannot verify this app", means the driver could not read the app's own program file to check it. That is security software holding the file open: add C:\Program Files\The Hidden Gaming Lair to its exclusions and restart the app.
Send a debug snapshot (menu ☰ → bug icon). Since version 16.2.1 it includes the driver health state and the last part of the Bridge Host service log, which records the exact reason a client was refused.
Please do not run the Companion App as administrator to work around this: it does not help detection (the driver handles that) and causes other issues.