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.