Undefined indexes

from issuupress.php, line 205:
if($_GET['documentId'] != '') {
should be
if(isset($_GET['documentId']) && $_GET['documentId'] != '') {

from issuupress.php, line 246:
$isInTags = (is_array($d->document->tags) && in_array($this->filterByTag, $d->document->tags));
should be
$isInTags = (isset($d->document->tags) && is_array($d->document->tags) && in_array($this->filterByTag, $d->document->tags));

from issuupress.php, line 259:
$selected = ($dId == $docId) ? 'class="issuu-selected"':'';
add

$selected = ($dId == $docId) ? 'class="issuu-selected"':'';
$link_target = '';

Turn on WP_DEBUG and WP_DEBUG_DISPLAY to see the errors ??

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