On a different hosting environment, I get:
[18-Dec-2018 13:06:42 Europe/Warsaw] PHP Fatal error: Uncaught Error: Call to a member function getProductType() on string in /home/klient.dhosting.pl/***/translatorium.***/www/lib/pkp/classes/plugins/PluginHelper.inc.php:107
Stack trace:
#0 /home/klient.dhosting.pl/***/translatorium.***/www/lib/pkp/controllers/grid/plugins/PluginGalleryGridHandler.inc.php(266): PluginHelper->installPlugin(NULL, 'Archiwum przes\xC5...')
#1 /home/klient.dhosting.pl/***/translatorium.***/www/lib/pkp/classes/core/PKPRouter.inc.php(390): PluginGalleryGridHandler->installPlugin(Array, Object(Request))
#2 /home/klient.dhosting.pl/***/translatorium.***/www/lib/pkp/classes/core/PKPComponentRouter.inc.php(257): PKPRouter->_authorizeInitializeAndCallRequest(Array, Object(Request), Array)
#3 /home/klient.dhosting.pl/***/translatorium.***/www/lib/pkp/classes/core/Dispatcher.inc.php(134): PKPComponentRouter->route(Object(Request))
#4 /home/klient.dhosting.pl/***/translatorium.***/www/lib/pkp in /home/klient.dhosting.pl/***/translatorium.***/www/lib/pkp/classes/plugins/PluginHelper.inc.php on line 107
[18-Dec-2018 13:10:33 Europe/Warsaw] PHP Fatal error: Uncaught Error: Call to undefined method TranslatorPlugin::getTemplateResource() in /home/klient.dhosting.pl/***/translatorium.***/www/plugins/generic/translator/controllers/grid/LocaleGridHandler.inc.php:108
Stack trace:
#0 /home/klient.dhosting.pl/***/translatorium.***/www/lib/pkp/classes/core/PKPRouter.inc.php(390): LocaleGridHandler->index(Array, Object(Request))
#1 /home/klient.dhosting.pl/***/translatorium.***/www/lib/pkp/classes/core/PKPComponentRouter.inc.php(257): PKPRouter->_authorizeInitializeAndCallRequest(Array, Object(Request), Array)
#2 /home/klient.dhosting.pl/***/translatorium.***/www/lib/pkp/classes/core/Dispatcher.inc.php(134): PKPComponentRouter->route(Object(Request))
#3 /home/klient.dhosting.pl/***/translatorium.***/www/lib/pkp/classes/core/PKPApplication.inc.php(247): Dispatcher->dispatch(Object(Request))
#4 /home/klient.dhosting.pl/***/translatorium.***/www/index.php(68): PKPApplicatio in /home/klient.dhosting.pl/***/translatorium.***/www/plugins/generic/translator/controllers/grid/LocaleGridHandler.inc.php on line 108
PHP 7.0