It is just the end of line character format which differs in dos,unix,mac.
From what the vim website tells me about it and what I remember, the “CR” character is present in the “dos” and “mac” file formats.
http://vim.wikia.com/wiki/File_format
You can specify the end of line characters used in notepad++ with “Edit -> EOL Conversion” and I think that using “UNIX format” can solve this.
I still got “Invalid Header” issues with the last version of the plugin.
I solved it by replacing all the carriage return “Ctrl+M” by the regular “\r” character.
In vim ‘:%s/^M/\r/g‘ where ‘^M‘ is obtained by doing Ctrl+v then Enter.
For information, I am working on a linux, the wordpress is hosted on a linux too and that may explain why it does not like the “Ctrl+M”.
And for what I have seen, the other plugins I have downloaded use the regular carriage return character and not the “Ctrl+M”
You can find here (for one month) the modified version that worked for me. https://transfert.inria.fr/fichiers/53aaff2a28284957c6c9167c234e97e2/user-meta-shortcodes.0.2.3.zip
