Forum .LRN Q&A: Problems with Kelp theme on dotLRN 2.3

I've activated the theme on the db, copied the files, but when I change the DefaultMaster parameter in the Main Site
it gives me the following error:

can't read "doc(title)": no such element in array
while executing
"ns_striphtml $doc(title)"
invoked from within
"set doc(title) [ns_striphtml $doc(title)]"
("uplevel" body line 67)
invoked from within
"uplevel {
ad_page_contract {
This is the top level master template. It allows the basic parts of an XHTML
document to be set through conv..."
(procedure "code::tcl::/var/lib/aolserver/r.fabi/www/blank-master" line 2)
invoked from within
"code::tcl::$__adp_stub"
invoked from within
"if { [file exists $__adp_stub.tcl] } {

# ensure that data source preparation procedure exists and is up-to-date
adp_init tcl $__adp_stub
..."
("uplevel" body line 3)
invoked from within
"uplevel {

if { [file exists $__adp_stub.tcl] } {

# ensure that data source preparation procedure exists and is up-to-date
adp_init t..."
(procedure "adp_prepare" line 2)
invoked from within
"adp_prepare"
invoked from within
"template::adp_parse $__adp_master [concat [list __adp_slave $__adp_output] [array get __adp_properties]]"
invoked from within
"template::adp_parse $__adp_master [concat [list __adp_slave $__adp_output] [array get __adp_properties]]"
invoked from within
"template::adp_parse $__adp_master [concat [list __adp_slave $__adp_output] [array get __adp_properties]]"
invoked from within
"template::adp_parse [file root [ad_conn file]] {}"
(procedure "adp_parse_ad_conn_file" line 5)
invoked from within
"$handler"
("uplevel" body line 2)
invoked from within
"uplevel $code"
invoked from within
"ad_try {
$handler
} ad_script_abort val {
# do nothing
}"
invoked from within
"rp_serve_concrete_file [ad_conn file]"
(procedure "rp_serve_abstract_file" line 60)
invoked from within
"rp_serve_abstract_file "$root/$path""
("uplevel" body line 2)
invoked from within
"uplevel $code"
invoked from within
"ad_try {
rp_serve_abstract_file "$root/$path"
set tcl_url2file([ad_conn url]) [ad_conn file]
set tcl_url2path_info..."

Any suggestion?
Thank you,
Roberto