[Zope] Proxy-role????

Hello, I wanted to change a method (code-><a href="Datenbank/index_html">Zurueck zur Einstiegsseite</a>)because I had changed the Objectname.The role was manager with all the premissions, but Zope didn't want me to do that!! Message of Zope ->"You are not authorized to change link_home because you do not have proxy roles. " Why???? Thanks.