You are seeing the below error message when attempting to create a contact or publish an invoice.
Object reference not set to an instance of an object.
This error is typically caused by an internal setting/piece of code being changed within your accounts package.
To clear this error, all you will need to do is reset your company's integration and republish your invoices.
Sage 50 users will need to disconnect and reconnect their company via the AutoEntry Desktop Sync App.
Users of all other integrations will need to disconnect and reconnect via the AutoEntry website.
Republish the affected invoices in your inbox.