XWiki 7.1.1 doesn't work when used as root application

I have the issue on 2 different wiki, both of them are installed as ROOT application.

We are using the xwiki package from the official repository (deb http://maven.xwiki.org stable/) on Debian.

The only modification from vanilla install is that I renamed the file /etc/tomcat7/Catalina/localhost/xwiki.xml to /etc/tomcat7/Catalina/localhost/ROOT.xml and the content was changed from:

<Context path="/xwiki" docBase="/usr/lib/xwiki" privileged="true"
  allowLinking="true" crossContext="true">
  <!-- make symlinks work in Tomcat -->
  <Resources className="org.apache.naming.resources.FileDirContext"
    allowLinking="true" />
</Context>

To

<Context path="/" docBase="/usr/lib/xwiki" privileged="true"
  allowLinking="true" crossContext="true">
  <!-- make symlinks work in Tomcat -->
  <Resources className="org.apache.naming.resources.FileDirContext"
    allowLinking="true" />
</Context>

First issue:

• during update from 7.0.1 to 7.1.1, several failed to update (LDAP, PDFexport and one an other that I forgot)
• after update, wysiwig is not working (the editor does not open)
• the comments, annotations, attachments, history and information pane does not work correctly: no comments are shown ever, the only attachment shown on every pages are the one on the undefined page (/bin/download/Interne/undefined/attachment), when uploading a new attachment, it is uploaded to the same location /bin/download/Interne/undefined/attachment_name
• the extension updater doesn't work, when I click "Check for Updates", it begins then never complete, I have to hit refresh to get the list of extension that need an update and then when I try to click the button to update them, nothing happens

When changing back the file /etc/tomcat7/Catalina/localhost/ROOT.xml to its original name and content, everything works without any issue.

Thomas told me to replace /usr/lib/xwiki/WEB-INF/lib/xwiki-platform-url-container-7.1.1.jar by the latest snapshot /http://maven.xwiki.org/snapshots/org/xwiki/platform/xwiki-platform-url-container/7.1.2-SNAPSHOT/xwiki-platform-url-container-7.1.2-20150817.123119-25.jar but this didn't solve the issue so this ticket is not a duplicate of XWIKI-12342 .

EDIT: corrected typos