I dont understand what you mean by "last line" in the read me, last line as in the bottom line in the bat file? last line as on the last line of the could not find folder?
Viewing post in PRE-FLIGHT — FS25 dependency scanner comments
If you run the .bat and it can not find your folder you need to right click the .bat and choose edit with notepad. The line will be in there and you set your directory path there. It currently is set to
powershell.exe -NoProfile -ExecutionPolicy Bypass -File "%~dp0FS25-PreFlight.ps1" add -ModsDir "D:\FS25\mods" or what ever your mods folder location is.