it would also be great if you could migrate your adm templates to the new template format .admx.
I agree, when I attempt to use the utility Microsoft provides it errors out with no defaults provided.
The ADM files provided in the project are missing the SUPPORTED keyword below the POLICY keyword. The admx conversion parser expects the SUPPORTED keyword to convert it to the new SUPPORTEDON node in the XML which is the ADMX file. XML parsers are VERY picky, thus why all the failures. We got them to convert with this fix, but have yet to import and apply the GPO. I do not know what value might be expected for the supported on keyword.