Error when creating single markdown page

[JeKo]

I just download the v0.14 .deb file for 64bits system and dpkg -i on it.
Then I tried to create a single markdown page and all I got is this error :

$ crowbook --lang en -s text.md
CROWBOOK 0.14.0
X text.md: Could not find file 'text.md' for book chapter
ERROR text.md: Could not find file 'text.md' for book chapter

[Lizzie Crowdagger]

Does the file "text.md" exist? I get this error when it doesn't exist.