Strange characters in Notepad++

Question

From this morning something strange is happening to my Notepad++ editor. When I press ↵ Enter on the keyboard I get some strange symbols:

What can I do to fix this?

Answer 1

it's an view option, turn it off via view -> "show end of line"

Answer 2

Indeed, you're seeing control characters in your view. Just for fun, a little bit of CR/LF history.

Answer 3

You've probably turned on some mode that displays control characters. CR-LF (\r\n in C parlance) is the standard end-of-line sequences in Windows.