Due to updates made by Apple, an overhaul of the Declick, Dehum, and Denoise plugins was necessary before the release of Audio Hijack 3.6. While our updated plugins perform similarly to the old versions, they are not drop-in replacements.
Sessions which contain these plugins have been automatically updated to use the new versions. The new plugins are off by default, to allow you to test and modify the settings.
For more details, please see this link.