[Zope] Plone update

Fri Sep 30 18:49:25 EDT 2005

I'm running Plone 2.0.5 with Zope 2.7.7-final and tried to
upgrade to Plone 2.1. A dry-run of portal_migration stopped
with errors :

Products/ATContentTypes/migration/common.py", line 105, in unrestricted_rename
    action ='manage_main')
Copy Error:
<HTML>
<HEAD>
<TITLE>Invalid Id</TITLE>
</HEAD>
<BODY BGCOLOR="#FFFFFF">
<FORM ACTION="manage_main" METHOD="GET" >
<TABLE BORDER="0" WIDTH="100%" CELLPADDING="10">
<TR>
  <TD VALIGN="TOP">
  <BR>
  <CENTER><B><FONT SIZE="+6" COLOR="#77003B">!</FONT></B></CENTER>
  </TD>
  <TD VALIGN="TOP">
  <BR><BR>
  <CENTER>
  The id "de_MIGRATION_" is not allowed.
  </CENTER>
  </TD>
</TR>
<TR>
  <TD VALIGN="TOP">
  </TD>
  <TD VALIGN="TOP">
  <CENTER>
  <INPUT TYPE="SUBMIT" VALUE="   Ok   ">
  </CENTER>
  </TD>
</TR>
</TABLE>
</FORM>
</BODY></HTML>
...
...
The upgrade path did NOT reach current version
Migration has failed

What's wrong here? Every hint is welcome.