By renaming this file to "do_trace.txt", you can force Addictive Drums 2 (AD2) to trace/log additional information about what it's doing.
This is useful for the XLN developers to get more information when AD2 isn't working as expected.
Next time AD2 is run, it will create a log text file in:
Windows: My Documents\Addictive Drums 2 Logs\
OS X: /Users/<user>/Library/Logs/Addictive Drums 2 Logs/
There will be a red "..TRACING IS ON" text at the bottom of the AD2 interface to indicate this mode.
Remember to restore the name back to "dont_trace.txt" (or simply trash the "do_trace.txt" file if both files exist), since it slows down a lot of things!