Index: /views/mods/mod_abo/order_view_base.phtml
===================================================================
--- /views/mods/mod_abo/order_view_base.phtml	(revision 8227)
+++ /views/mods/mod_abo/order_view_base.phtml	(revision 8229)
@@ -8,5 +8,5 @@
 <tr class="wpsg_<?php echo (($this->view['i'] == 0)?'odd':'even'); ?>">
 	<td ><?php echo __('Abo VerlÀngerungen', 'wpsg'); ?>:</td>
-	<td align="right" colspan="<?php echo ((sizeof($this->view['basket']['mwst']) > 1 || $this->get_option('wpsg_showMwstAlways') == '1')?'4':'3'); ?>">
+	<td align="right" colspan="<?php echo ((sizeof($this->view['basket']['mwst'])??0 > 1 || $this->get_option('wpsg_showMwstAlways') == '1')?'4':'3'); ?>">
 		<?php if (wpsg_isSizedArray($this->view['wpsg_mod_abo']['rebuy'])) { ?>
 		<?php foreach ($this->view['wpsg_mod_abo']['rebuy'] as $k => $v) { ?>