Software error:

isa check for "display_name" failed: undef is not a string! at (eval 72) line 73.
	eval {...} called at (eval 72) line 72
	Delti::Webtracking::Product::new('Delti::Webtracking::Product', 'unit_sales_price', undef, 'product_dimension', undef, 'product_category', undef, 'item_id', 'ZUB-53563', ...) called at Delti/Webtracking/Simple.pm line 87
	Delti::Webtracking::Simple::push_display_items('Delti::Webtracking::Simple=HASH(0x298c280)', 'item_id', 'ZUB-53563', 'display_name', undef, 'quantity', 1, 'unit_sales_price', undef, ...) called at Delti/Webtracking/Util.pm line 162
	Delti::Webtracking::Util::tracking_push_displayitem(100, 'ZUB-53563', undef, undef, 'ARRAY(0x369d338)', undef, 1, undef) called at ./LibShop/RD-ZUB_main.pl line 170
	require ./LibShop/RD-ZUB_main.pl called at /srv/www/cgi-bin/rzub.pl line 20

For help, please send mail to the webmaster (webmasterswebc27@delti.com), giving this error message and the time and date of the error.

Software error:

[Thu Aug 24 04:52:11 2017] rzub.pl: isa check for "display_name" failed: undef is not a string! at (eval 72) line 73.
[Thu Aug 24 04:52:11 2017] rzub.pl: 	eval {...} called at (eval 72) line 72
[Thu Aug 24 04:52:11 2017] rzub.pl: 	Delti::Webtracking::Product::new('Delti::Webtracking::Product', 'unit_sales_price', undef, 'product_dimension', undef, 'product_category', undef, 'item_id', 'ZUB-53563', ...) called at Delti/Webtracking/Simple.pm line 87
[Thu Aug 24 04:52:11 2017] rzub.pl: 	Delti::Webtracking::Simple::push_display_items('Delti::Webtracking::Simple=HASH(0x298c280)', 'item_id', 'ZUB-53563', 'display_name', undef, 'quantity', 1, 'unit_sales_price', undef, ...) called at Delti/Webtracking/Util.pm line 162
[Thu Aug 24 04:52:11 2017] rzub.pl: 	Delti::Webtracking::Util::tracking_push_displayitem(100, 'ZUB-53563', undef, undef, 'ARRAY(0x369d338)', undef, 1, undef) called at ./LibShop/RD-ZUB_main.pl line 170
[Thu Aug 24 04:52:11 2017] rzub.pl: 	require ./LibShop/RD-ZUB_main.pl called at /srv/www/cgi-bin/rzub.pl line 20
Compilation failed in require at /srv/www/cgi-bin/rzub.pl line 20.

For help, please send mail to the webmaster (webmasterswebc27@delti.com), giving this error message and the time and date of the error.