leather-dev skins and view/viewHelper plugins

[Miroslav Mocek]

Hello,

I've just downloaded forrest 0.7. I've tried to create my own site. I've 
tried to change skin in forrest.properties.

I saw screenshots in documentation, the leather-dev skin is what I want 
(http://forrest.apache.org/docs_0_70/images/snapshot-view-viewHelper.png) 
but I'm not able to get it.

If I edit forrest.properties like this:
project.skin=leather-dev

start forrest run and use browser to view localhost:8888, i get Internal 
Server Error :
<>Message: null
Description: No details available.
Sender: org.apache.cocoon.servlet.CocoonServlet
Source: Cocoon Servlet
Request URI index.html
cause Chyba funkce ElemTemplateElement: getHead
request-uri /index.html

I've tried to edit this line:
project.required.plugins=org.apache.forrest.plugin.output.pdf,org.apache.forrest.plugin.internal.view

the plugin was downloaded and installed. But I get the same Internal 
Server Error.

There is written in documentation, that I need also viewHelper plugin, 
but I haven't found it.

What's wrong? How can I get the leather-dev skin on my site?
Thank You
Mirek