The latest version of macOS X (10.13 - High Sierra) implements a new security feature which affects Camtasia's ability to install the TechSmith System Audio Capture kernal extension.
If you are on macOS High Sierra 10.13 please update to Camtasia 3.1.2. To update, select Camtasia 3 > Check for Updates. If the problems continue, please try the suggestions below:
Unable to Record System Audio
Option 1: Allow in Security & Privacy
- Select Camtasia 3 > Preferences > Recording and click Install component.
- Click Install.
- Click Open Security & Privacy.
- Click Allow, and then enter your computer password.
- Try recording system audio in Camtasia.
Camtasia may prompt to install the component again. If so, follow the steps to install the component again.
Option 2: Remove Old Extension
- Open a Finder window.
- Select Go > Go to folder from the menu bar.
- Type the following and click Go:
- Move the TACC.kext file to the Trash. Empty the trash.
- Restart the computer.
- Repeat the steps in Option 1 to install the system audio component.