LoadError html/sanitizer

Hi, do you have a idea?
This problem appeared today, but yesterday it was ok, and I changed

LoadError in Demandes#show

/home/caritas/public_html/web_gdc/app/views/demandes/show.html.erb where
line #12 raised:

no such file to load -- html/sanitizer

Extracted source (around line #12):

9: <p><b>nom_folders: </b><%= @demande.nom_folders %></p>
10: <p><b>nom_taches: </b><%= @demande.nom_taches %></p>
11: <p><b>nom_problems: </b><%= @demande.nom_problems %></p>
12: <p><b>commentaires: </b><%= simple_format(@demande.commentaires)
13: <p><b>Created_at: </b><%=
@demande.created_at.localtime.strftime("%d/%m/%Y (%Hh%M)") %></p>
14: <p><b>Updated_at: </b><%=
@demande.updated_at.localtime.strftime("%d/%m/%Y (%Hh%M)") %></p>
15: <p><b>log:</b><%= simple_format(@demande.log) %></p>

I'm also having this problem. It has been solved by using bundler 1.0.7
instead of 1.0.8...


But how to downgrade Bundler?
The bugs is reported on Github?

I found it on git