On my site the view print order and invoice order go on error, on the log there is this info:
2019-09-27T10:11:04+00:00 CRITICAL 185.49.249.11 error Uncaught \Throwable of type Error thrown. Stack trace: #0 /home/gardenor/public_html/libraries/joomla/event/event.php(70): plgSystemSellaciousTemplateOrder->onParseViewTemplate('com_sellacious....', Object(Joomla\Registry\Registry), '')
#1 /home/gardenor/public_html/libraries/joomla/event/dispatcher.php(160): JEvent->update(Array)
#2 /home/gardenor/public_html/components/com_sellacious/layouts/views/order/print.php(30): JEventDispatcher->trigger('onparseviewtemp...', Array)
#3 /home/gardenor/public_html/libraries/sellacious/view/view.php(258): include('/home/gardenor/...')
#4 /home/gardenor/public_html/libraries/src/MVC/View/HtmlView.php(230): SellaciousView->loadTemplate(NULL)
#5 /home/gardenor/public_html/libraries/sellacious/view/view.php(143): Joomla\CMS\MVC\View\HtmlView->display(NULL)
#6 /home/gardenor/public_html/components/com_sellacious/views/order/view.html.php(98): SellaciousView->display(NULL)
#7 /home/gardenor/public_html/libraries/src/MVC/Controller/BaseController.php(672): SellaciousViewOrder->display()
#8 /home/gardenor/public_html/components/com_sellacious/controller.php(50): Joomla\CMS\MVC\Controller\BaseController->display(false, false)
#9 /home/gardenor/public_html/libraries/src/MVC/Controller/BaseController.php(710): SellaciousController->display()
#10 /home/gardenor/public_html/components/com_sellacious/sellacious.php(28): Joomla\CMS\MVC\Controller\BaseController->execute('')
#11 /home/gardenor/public_html/libraries/src/Component/ComponentHelper.php(402): require_once('/home/gardenor/...')
#12 /home/gardenor/public_html/libraries/src/Component/ComponentHelper.php(377): Joomla\CMS\Component\ComponentHelper::executeComponent('/home/gardenor/...')
#13 /home/gardenor/public_html/libraries/src/Application/SiteApplication.php(194): Joomla\CMS\Component\ComponentHelper::renderComponent('com_sellacious')
#14 /home/gardenor/public_html/libraries/src/Application/SiteApplication.php(233): Joomla\CMS\Application\SiteApplication->dispatch()
#15 /home/gardenor/public_html/libraries/src/Application/CMSApplication.php(196): Joomla\CMS\Application\SiteApplication->doExecute()
#16 /home/gardenor/public_html/index.php(49): Joomla\CMS\Application\CMSApplication->execute()
#17 {main}