Your antivirus may block access to essential files for your audio application or the MERGING+NADAC driver, which prevents the application or the MERGING+NADAC driver to start and/or run properly.
The antivirus might be sometimes too cautious, and block or quarantine a file that is clean (false positive).
Nowadays antivirus have their databases updated very often, up to several times a day.
That means that even if MERGING+NADAC or your application was working fine yesterday that this issue may not arise.
By default, Windows is installed with its own antivirus, called Windows Defender.
Most part of the antivirus available today allows to create exclusions, so specific folders or files are not scanned by the antivirus.
You should exclude programs only if you are confident that they are not infected.
Merging products, including MERGING+NADAC and Emotion, do not contain virus.
See below for the Windows embedded antivirus, Defender, or click here for third party antivirus (Norton, McAfee, Avast, Kaspersky,....)
...