DND = Do Not Disturb

writing in these files can cause that the program won't start

the default.conf should never be written so that you alway have 
something to start this program with

save your own settings please with the menu under "config > main > save as..."
in the "config/general folder" , not here. You are encouraged to play with them,
and if there are good you can load them with "config > main > load from..." 
and they will become autosaved.conf