How do I disable Notepad++'s "This file has been modified..." message? [duplicate]
Settings -> Preferences -> MISC. tab
In the section that says File Status Auto Detection
make sure that Enable
is unchecked
Settings → Preferences → Misc. → Uncheck Enable under File Status Auto-Detection
Also, as Jet pointed out, you can also have 'Update silently' checked if you want it to auto-update the file.