After installing Windows updates on the Windows servers, a growing number of users are reporting that parts of the Outlook Add-in for NoSpamProxy are no longer displayed. However, the add-in seems to be installed correctly and functioning a expected.
With the latest Windows updates, Microsoft has tightened the security settings for access to group policies. As a result, users can no longer retrieve them. Microsoft describes the solution in its Knowledge Base: https://support.microsoft.com/en-us/topic/ms16-072-security-update-for-group-policy-june-14-2016-7570425d-d460-3003-b2ac-a464c874725d