2022-11-16 15:16:52 [wst1][appstack][ERR] Error calling the Start method of the MqttServer data source:
System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
at System.Collections.Generic.List
1.Enumerator.MoveNext()
at Scada.Comm.Engine.CommLine.SelectDevices()
at Scada.Comm.Drivers.DrvDsMqtt.Logic.MqttDSL.FillDeviceTopics()
at Scada.Comm.Drivers.DrvDsMqtt.Logic.MqttDSL.Start()
at Scada.Comm.Engine.DataSourceHolder.Start()
Does this error appear every time when you restart Communicator?