This issue has to do with the Audio Preferences not caching correctly. If you delete your Liquid Loops Audio Engine Preference files, then on the next startup of Liquid Rhythm the audio will be back.
- Find all Liquid Loops Audio Engine Preferences files, and delete any you encounter.
See below for all possible locations of these files on both macOS and Windows.
macOS
/Library/Application Support/LiquidLoops Audio Engine Preferences
/Library/Application Support/Liquid Loops Max 8 Preferences
/Users/<username>/Library/Application Support/LiquidLoops Audio Engine Preferences
/Users/<username>/Library/Application Support/Liquid Loops Max 8 Preferences
Windows
C:\Users\<username>\AppData\Roaming\Cycling '74\LiquidLoops Audio Engine Preferences Files
C:\Users\<username>\AppData\Roaming\Cycling '74\Liquid Loops Max 8 Preferences