Mistake on my document, and not in internet

1

When LangageTool check my document, it don’t find any error, bit it is missing an s to membres (it is plural)
Les membre de

When I chek on internet this text, LangageTool find the error !

What’s wrong in my document.

For information.
the text comme from internet by a copy, past.

I am un Unbuntu 14.04, and Libre Office 4.4

Best regard.

2

Thanks for your report. Could you upload the document somewhere, or send it to me directly (naber at-sign danielnaber de) so I can look at it?