Updated a group analysis error message.
Updated a group analysis error message.

roijo/C-PAC_complexitytools,danlurie/C-PAC,danlurie/C-PAC,roijo/C-PAC_complexitytools,roijo/C-PAC_complexitytools,danlurie/C-PAC,roijo/C-PAC_complexitytools,danlurie/C-PAC