Using a text file containing several (17) newline characters only, the replace all function failes to locate any of the newlines when regular expression is selected. When extended is selected the find/replace works correctly.
Screenshot of Error
I have also reproduced this bug in Notepad++ 5.3.1
Repro as follows:
1. Create plain text file with Windows line endings. Enter a few lines of text.
2. In Notepad++ select "View-Show End of Line" to verify the CRLF line endings
3. Search - Find...
4. Check the box for a regular expression search and enter \r\n as the search string.
5. Click Find Next and no line will be found.
The ScITE regex reference indicates that the \r\n syntax is allowed but it doesn't work in Scintella 2.01 either.
The impact of being unable to match line endings is that it is impossible to remove lines that match a certain expression - you can remove the content but you are left with the CRLF.