Issues saving appointments that are created via GUI

Hello!

I'm currently experiencing some major issues in a customer environment(online) since the last SuperOffice update.
I'm no longer able to save any appointments that has been created by the users via the GUI, I and the users are still able to edit these appointments via the GUI.

Appointments that are created by CRMScripts can still be edited via CRMscripts.

try{
  Integer appointmentId = 12129;
  NSAppointmentAgent appointmentAgent;
  NSAppointmentEntity appointmentEntity = appointmentAgent.GetAppointmentEntity(appointmentId);
  appointmentAgent.SaveAppointmentEntity(appointmentEntity);
}
catch{
  log("Error: " + error);
  printLine(error);
}

Running above code on an appointment created via GUI results in the following:

No error is ever printed or logged, the icon just keeps spinning.

I have checked all of the extrafields connected to Follow-up and none of them are mandatory.

I have also checked that the NSAppointmentEntity is loaded by the agent:

try{
  Integer appointmentId = 12129;
  NSAppointmentAgent appointmentAgent;
  NSAppointmentEntity appointmentEntity = appointmentAgent.GetAppointmentEntity(appointmentId);
  printLine(appointmentEntity.GetCompleted().toString());
  //appointmentAgent.SaveAppointmentEntity(appointmentEntity);
}
catch{
  log("Error: " + error);
  printLine(error);
}

Has anyone else experienced any similiar issues or have any suggegestions on how to proceed to solve the problem?