You're getting an empty string back from this section of code:
set server_name [ns_info server]
append config_path "ns/server/" $server_name "/acs/redirect"
set all_the_redirects [ns_configsection $config_path]
ns_log Notice "/tcl/ad-redirect.tcl has found [ns_set size $all_the_redirects] redirects specified in $config_path"
Which indicates that your server name is not set correctly. Did you
rename and configure service-name.ini and ad.ini?
