Load langs.xml Failed
This error usually results from the langs.xml file being truncated to 0 bytes. This seems to happen prevalently on laptops and in UAC-enabled systems, specially Win 7.
Notepad++ was fixed in version 6.1.7, so this issue should not appear on versions equal or greater than this. Upgrading older versions has plenty of other benefits as well.
Copying langs.model.xml as langs.xml (they are in %APPDATA%\Notepad++) has been reported to fix the issue.