Encountered this problem:

A fatal error has occured:

ARRAY (1144): Unknown method 'Dumper' called at ....

with this code:

sub user_signup {
# -------------------------------------------------------------------
# This subroutine will get called whenever the hook 'user_signup'
# is run. You should call GT::Plugins->action ( STOP ) if you don't
# want the regular code to run, otherwise the code will continue as
# normal.
#
my (@args) = @_;GT::Plugins->action ( STOP );
print $IN->header();
require GT::Dumper; print Dumper(\@args); }