Blank screen with tabs enabled?

I'm probably doing something wrong on my end.

Setup: Created mini-panel with two panes, each custom info.
Problem: When I select the display of tabs in mini panel and preview it, I get a white screen. Any other display and it works (but no tabs of course)
Goal: tabbed mini-panels like http://wimleers.com/demo/mini-panels#tabs-mini-panel-demo_tabs-demo_tabs-2
Background: I'm using 5.x-2.0-beta5 and Views 5.x-1.6.
Troubleshooting: I followed the README. I've switched to Garland.
More info: I've exported my view below:
==============

$mini = new stdClass();
$mini->pid = 'new';
$mini->name = 'tabst';
$mini->title = 'tabst';
$mini->requiredcontexts = array();
$mini->contexts = array();
$mini->relationships = array();
$display = new panels_display();
$display->did = 'new';
$display->name = NULL;
$display->layout = 'onecol';
$display->layout_settings = NULL;
$display->panel_settings = array (
'style' => 'tabs',
'style_settings' =>
array (
),
'edit_style' => 'Edit style settings',
'individual' => 0,
'panel' =>
array (
'middle' =>
array (
'style' => '',
'edit_style' => 'Edit style settings',
),
),
'did' => '46',
);
$display->content = array();
$display->panels = array();
$pane = new stdClass();
$pane->pid = 'new-1';
$pane->panel = 'middle';
$pane->type = 'custom';
$pane->subtype = 'custom';
$pane->access = array();
$pane->configuration = array (
'override_title' => 0,
'override_title_text' => '',
'css_id' => '',
'css_class' => '',
'title' => 'Test',
'body' => 'asdfasdfasdfasdfasdfasdf',
'format' => '1',
);
$pane->shown = '1';
$pane->visibility = '';
$display->content['new-1'] = $pane;
$display->panels['middle'][0] = 'new-1';
$pane = new stdClass();
$pane->pid = 'new-2';
$pane->panel = 'middle';
$pane->type = 'custom';
$pane->subtype = 'custom';
$pane->access = array();
$pane->configuration = array (
'override_title' => 0,
'override_title_text' => '',
'css_id' => '',
'css_class' => '',
'title' => 'aaaaaaa',
'body' => 'bbbbbbb',
'format' => '1',
);
$pane->shown = '1';
$pane->visibility = '';
$display->content['new-2'] = $pane;
$display->panels['middle'][1] = 'new-2';
$mini->display = $display;