Plugin don't work with OJS 3.1.2

[bolelligallevi]

Hi,

once installed the click on "Settings" shows the error "Ajax request or invalid JSON returned", and no settings page is loaded.

With plugin author help I tried to manage the smarty problem about the change of the names of functions sending data to templates (i.e 3.1.2: parent::__construct($plugin->getTemplateResource('settingsForm.tpl')); instead of 3.1.1:
parent::__construct($plugin->getTemplatePath() . $sf);), modifying the files \nbn-master\NBNPubIdPlugin.inc.php and \nbn-master\classes\form
plugin.zip
NBNSettingsForm.inc.php (see attached files).
Unfortunately the plugin is still not working, after Ajax error the PHP logs are:
AH01071: Got error
PHP message: PHP Warning: Declaration of NBNPubIdPlugin::getTemplateResource() should be compatible with Plugin::getTemplateResource($template = NULL, $inCore = false) in /plugins/pubIds/nbn/NBNPubIdPlugin.inc.php on line 0
PHP message: PHP Fatal error: Uncaught --> Smarty: Unknown resource type 'plugins-plugins-pubIds-nbn-pubIds-nbn' <--
thrown in /lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_resource.php on line 112', referer: https://ojs-unimi-test.4science.cloud/index.php/AMonline/management/settings/website

Can anyone help?
Best regards,
Stefano Bolelli Gallevi
plugin.zip