The type or namespace name `DarkTonic' could not be found. Are you missing an assembly reference?
The 'DarkTonic' namespacebelongs to MasterAudio.
You are getting this issue because you enabled support for the 3rd party asset MasterAudio and it was not installed in your project.
You can fix this issue in two ways:
-- You can install the MasterAudio asset from the Asset Store and this will add the missing namespace
-- You can delete from your Scripting Define Symbols the text 'dUI_MasterAudio'
-- look at the top bar -> Edit -> Project Settings -> Player -> look in the Inspector View -> open the horizontal tab named 'Other Settings' -> look for 'Scripting Define Symbols' -> delete the string 'dUI_MasterAudio' -> press Return (Enter)