Hi SimFlyers,
Earlier today we identified the cause of the issue: a temporary timeout occurred during the communication between SimFly and SimBrief. This prevented the system from retrieving the flight plan and triggered the Error.Server.ConnectionRefused message for some missions.
The error has now been fully resolved.
If you still see it, simply refresh the page and the mission modal will appear correctly again.
For new missions, the error will no longer occur.
This incident also gave us the opportunity to improve the system: we are already working on separating these two functionalities so that any delays between SimFly and SimBrief will no longer affect the ability to complete a mission.
Thank you for your patience and cooperation.