Symptom:
Error thrown  while fetching history of available trace.

Conditions:
"1: Login to Intracer GUI and navigate to Configure -> LTE Trace >  Real Time Trace Config.
Enable ""Enable Real Time Trace"" check box, make sure ""Node CPU Threshold""=75% and ""Trace Path"" is configured.
2:Navigate to Trace > 3GPP Trace > Real Time Traces > New  and enter valid details and click on Save button.
Ex: Name = RTT_Test
Duration= 5 mins
Node = TestNode (Make sure this LTE node should be configured prior to this step)
Trace Type = Active 
Subscriber Id type = IMSI
Subscriber Id value = 123456789012345
3: Select this configured RTT and click on start. 
4: Create a LTE session based on the node configuration and verify if the traces are captured. 
5: Wait till the configured duration. Click on History button to see the captured traces."
6: Try the above steps with multiple GWs.