Hi Adrien,
After migrating a client from version 6.x to 8.1 an issue arrises every morning. Users with privilege are being blocked by the proxy service. The message is: "Wingate has blocked [URL] because rule Default Rule denied access to category unknown". A simple restart of Wingate service solves the problem for all connected PC´s. Those PC´s that are not active during the restart procedure will be blocked when active. A further Wingate restart will solve the issue for users that were not connected initially.
We revised a case in particular with granted access to all websites execpt youtube.com. This PC was blocked the next day to ALL websites. A simple restart solved the problem for the day. I am attaching screenshots for your review.
Thank you