Upgrading to R2 yields adprep errors: "Adprep will not extend your existing schema" The error messages mention "Vintela-" in the name
Before R2 was available the Vintela rfc2307 attributes, needed to be installed. Microsoft agreed to include this schema in with the operating system as rfc2307. Therefore if the legacy Vintela rfc2307 exists, the LDIF scripts will need to be run to rename the attributes.
1 - Read the ldif scripts with a standard text editor
2 - Run our ldif scripts to rename the attributes before continuing with adprep.
The ldif files are located in the Authentication Services product download under the /windows/ldif location
Once these additional schema modifications are completed you will be able to finish your R2