Adding calendar field to meta data causes XML error
When calendar field is set to be a time period field and we set it to add data to the meta description or keys, there appear following error at the front-end entry view:
0 Argument 1 passed to DOMNode::appendChild() must be an instance of DOMNode, null given
/home/srv17555/domains/srv17555.microhost.com.pl/public_html/components/com_sobipro/lib/mlo/template_xslt.php:308
Call stack
# Function Location
1 () JROOT/components/com_sobipro/lib/mlo/template_xslt.php:308
2 DOMNode->appendChild() JROOT/components/com_sobipro/lib/mlo/template_xslt.php:308
3 SPTemplateXSLT->createNode() JROOT/components/com_sobipro/lib/mlo/template_xslt.php:242
4 SPTemplateXSLT->createNode() JROOT/components/com_sobipro/lib/mlo/template_xslt.php:295
5 SPTemplateXSLT->createNode() JROOT/components/com_sobipro/lib/mlo/template_xslt.php:242
6 SPTemplateXSLT->createNode() JROOT/components/com_sobipro/lib/mlo/template_xslt.php:242
7 SPTemplateXSLT->createNode() JROOT/components/com_sobipro/lib/mlo/template_xslt.php:295
8 SPTemplateXSLT->createNode() JROOT/components/com_sobipro/lib/mlo/template_xslt.php:173
9 SPTemplateXSLT->createXML() JROOT/components/com_sobipro/lib/mlo/template_xslt.php:88
10 SPTemplateXSLT->display() JROOT/components/com_sobipro/lib/views/view.php:336
11 SPFrontView->display() JROOT/components/com_sobipro/lib/views/entry.php:44
12 SPEntryView->display() JROOT/components/com_sobipro/lib/ctrl/entry.php:737
13 SPEntryCtrl->details() JROOT/components/com_sobipro/lib/ctrl/entry.php:73
14 SPEntryCtrl->execute() JROOT/components/com_sobipro/lib/ctrl/sobipro.php:535
15 SobiProCtrl->execute() JROOT/components/com_sobipro/sobipro.php:47
16 require_once() JROOT/libraries/src/Component/ComponentHelper.php:402
17 Joomla\CMS\Component\ComponentHelper::executeComponent() JROOT/libraries/src/Component/ComponentHelper.php:377
18 Joomla\CMS\Component\ComponentHelper::renderComponent() JROOT/libraries/src/Application/SiteApplication.php:194
19 Joomla\CMS\Application\SiteApplication->dispatch() JROOT/libraries/src/Application/SiteApplication.php:233
20 Joomla\CMS\Application\SiteApplication->doExecute() JROOT/libraries/src/Application/CMSApplication.php:196
21 Joomla\CMS\Application\CMSApplication->execute() JROOT/index.php:49