For starters, use code tags:
Also that warning is… well a warning. Usually there should be a button to “correct” the issue and you can just click it and it will.
What it’s referring to is that Mac/unix system and Windows system use 2 different line endings.
Basically windows uses the 2 chars ‘carriage return’ ‘line feed’, often referred to as CRLF or \r\n.
Unix systems tend to just use the ‘line feed’, LF, \n.
The warning is stating that your line endings are inconsistent. This usually happens because Unity laid down a text file based on the unix standard, then you opened it in say Visual Studio and added a line to it using the windows standard. Meaning there is now lines following windows and lines following unix.
Again, there should be a button in that popup window to “correct” the problem. Click it, and it’ll go away.