[Crash] ipsec.exe (0xc0000005) hangs after SAML Auth - FortiClient 7.4.3 - Dell/MediaTek

Hi Community,

I am reaching out because I am hitting a wall with a specific client installation and I suspect a hardware/driver conflict, but I need confirmation or ideas on how to debug this further.

The Scenario: I am deploying an IPsec VPN configuration with SAML Authentication (Entra ID / Azure AD).

• Success: The exact same configuration works perfectly on an HP PC.

• Failure: It fails consistently on a specific Dell Laptop.

Environment (Failing Machine):

• Hardware: Dell Laptop

• Network Adapter: MediaTek Wi-Fi 6E MT7922 (Wireless LAN Card)

• OS: Windows 10/11 [Please confirm your OS version here, e.g., 22H2]

• FortiClient Version: VPN-only Client 7.4.3 (Build 1790) / Hotfix 1.8758

The Symptoms:

1. The user starts the VPN connection.

2. SAML Authentication window pops up (Microsoft Entra ID).

3. Authentication is successful.

4. The Issue: Immediately after the auth window closes, the FortiClient status hangs (stalls). It does not establish the tunnel.

5. After a short moment, nothing happens, or the connection attempt simply vanishes.

Logs & Analysis: The internal FortiClient logs are unhelpful; they stop right after the SAML authentication confirms "success" and do not show the tunnel negotiation failure.

However, the Windows Event Viewer reveals that ipsec.exe is crashing silently with an Access Violation error (0xc0000005).

Event Viewer Output:

Faulting application name: ipsec.exe, version: 7.4.3.1790, time stamp: 0x67db4333 Faulting module name: ipsec.exe, version: 7.4.3.1790, time stamp: 0x67db4333 Exception code: 0xc0000005 Fault offset: 0x000000000003d812 Faulting process id: 0x2D7C Faulting application path: C:\Program Files\Fortinet\FortiClient\ipsec.exe Faulting module path: C:\Program Files\Fortinet\FortiClient\ipsec.exe

Troubleshooting steps taken so far: To rule out corruptions, I have performed the following steps, but the result remains the same:

• Clean Install: Used the FCRemove Tool to completely wipe the client before every re-installation.

• Versions: Tried multiple previous versions of FortiClient (7.2.x, 7.0.x) – same behavior.

• Dependencies: Reinstalled and tried different versions of Visual C++ Redistributables (vcredist).

• Permissions: Tested with both Local Administrator and Standard User accounts.

Hypothesis: Given that this works on an HP machine (likely Intel/Realtek Wi-Fi) but crashes on the Dell with the MediaTek Wi-Fi 6E MT7922, I suspect a conflict between the ipsec.exe process and the MediaTek network driver stack.

Has anyone experienced similar crashes with MediaTek adapters? Are there any known workarounds or specific driver settings (Offload settings) that need to be disabled?

Any help would be greatly appreciated.

Thanks!