[LTSP] The home pages are not available at the address http://www/~username/

Hello

I'm using debian-edu (Jessie). The clients are connected on tjener via LTSP (diskless).
Eveything is ok except one thing: the home pages of users are not available at the address http://www/~username/:
For example, with the user name tt, the answer is: You don't have permission to access /~tt/ on this server.

-> The log on tjener:
# grep tt /var/log/apache2/error.log
[Thu Jan 12 09:36:36.990098 2017] [authz_core:error] [pid 689] [client 10.0.16.85:55433] AH01630: client denied by server configuration: /skole/tjener/home0/tt/public_html/

-> and the apache2/mods-available/debian-edu-userdir.conf

# cat /etc/apache2/mods-available/debian-edu-userdir.conf
<IfModule mod_userdir.c>
        UserDir public_html
        UserDir disabled root

        <Directory /skole/tjener/home*/*/public_html>
                AllowOverride FileInfo AuthConfig Limit
                Options MultiViews Indexes SymLinksIfOwnerMatch IncludesNoExec
        </Directory>
</IfModule>

-> the public_html on the pc's tt:

tt@auto-mac-44-8a-5b-c7-96-45:~$ ls -al ~/public_html/
total 20
drwxrwxr-x 1 tt tt 4096 janv. 12 09:39 .
drwxr-xr-x 1 tt tt 4096 janv. 12 12:44 ..
-rw-rw-r-- 1 tt tt 201 janv. 12 09:39 index.html
-rw-rw-r-- 1 tt tt 201 janv. 12 09:38 index.php
-rw-rw-r-- 1 tt tt 296 janv. 12 09:35 page.php

Thanks for help.