Go to your Antivirus settings and add the entire C:\Ross-Tech\ folder to the list. This prevents the antivirus from scanning and breaking the loader files in the future. Method 3: Fixing Driver and COM Port Mismatches

This guide will walk you through the causes and solutions to fix the "Failed 2" error and get your diagnostic setup running again in 2026. What Causes the "VCDS Loader Failed 2" Error?

Once you have a working setup, follow these tips to avoid encountering the error again:

Check your "Quarantine" folder; if the loader was flagged, restore the file and add the entire VCDS folder as an in your antivirus settings. Run as Administrator :

: Before launching the patch, add the entire C:\Ross-Tech folder to your Antivirus/Windows Defender Exclusion list. Set Advanced Outbound Firewall Rules : Open Windows Defender Firewall with Advanced Security . Click Outbound Rules -> New Rule . Select Program and browse to VCDS.exe and VCDSLoader.exe .

Use a dedicated tool or manual install to re-install the driver. The driver for clones is often provided alongside the loader. 5. Disable Driver Signature Enforcement (Windows 10/11) Windows 10/11 might block clone drivers.

Go to , find the Ross-Tech device, and select Uninstall device (check "Delete driver software"). Uninstall all VCDS and loader software from your PC.

Copy the Kolimer Loader file ( .exe ) into the VCDS installation folder.

For official hardware, Ross-Tech recommends using their VCI Config utility to force a firmware update if the interface becomes unresponsive during a standard update.

The Kolimer Loader is a custom tool designed to bypass the licensing checks of Ross-Tech’s official software, allowing clone cables (often with FTDI chips) to function as legitimate devices.