Dynamics 365 Portals - View Role Configuration - Error on portal access

Hello guys,

I created a portal instance and pointed it to a development instance on CRM, it was working but something changed - I don't know what exactly - and I'm getting the following error when I go to the portal URL. Does anyone have an idea of how the plugin "ViewRoleConfiguration" interferes in the portal?

Thank you!

Error message: "ViewRoleConfiguration.Plugin.PreRetrieveMultipleSavedQuery: Object reference not set to an instance of an object".