When trying to record in Camtasia this error occurs.
We have seen a specific component that comes included on most MSI computers called Nahimic Audio cause this error. We recommend closing out of that component (or uninstalling it) before launching and using Camtasia.
A second cause to this problem is a process called AWSoundCentersvc32.exe. Opening up task manager by hitting CTRL + SHIFT + ESC and exiting that process should allow Camtasia to avoid the error above.
来源： Camtasia (Windows): System Audio Setup Failed – TechSmith Support