You may enable the Debug File setting at the
checkbox in the Advanced Settings tab in the main window.

Alternatively, you may enable the option with the following command
line argument:
-
When you enable XXCLONE's debug file option, XXCLONE's
file I/O activities are recorded in the Debug File.
The contents of the Debug File are very similar (and mostly
redundant) to those of the Log File.
Its primary purpose is for Pixelab's engineer to analyze
the XXCLONE activities for troubleshooting purposes.
The entries in the debug file are mostly cryptic and
serves little purpose for ordinary users.
Unlike the Log File, the Debug File will be saved in
the root directory of the system volume (usually at
C:\XXCLONE.DBG) and only the last XXCLONE
session will be recorded in the file.