ADFS is rejecting the assertion from SM, complaining that the SPID was not passed in URI format. The SPID format is 'unspecified'.
Regardless of the attribute format, ADFS expects the SPID to be of the https://name.sub.domain format. As Siteminder doers not have such a limitation, the customer had configured a value without 'https://' in front of it.
Release: ESPSTM99000-12.51-Single Sign On-Extended Support Plus
Configure the SPID value to be URI format. It should look like a root URL: https://SPID.company.com