Are there common background applications or services that conflict with VRChat's anti-cheat, and how do I identify them?

Yes, certain background applications can conflict. Common culprits include: VPN software, overlay applications (e.g., Discord overlay, NVIDIA GeForce Experience overlay, MSI Afterburner), system monitoring tools, certain virtualization software, and other game launchers/clients. To identify conflicts, perform a clean boot of Windows (disabling all non-Microsoft services and startup items via MSConfig) and then try launching VRChat. If it works, re-enable services/apps in small batches until the conflict is found.