Hello how to fixe this issue  please  ==>

After launching chatbot session  i'm trying to trace this functionality  "download file" because it's not working wich is realted to pega rule i found this bug in log file

 [     default task-21] [  STANDARD] [                    ] [                    ] (      internal.mgmt.Executable) FATAL frljbs700014.retraite.lan|null  - Usage error - popping Executable that is not current 

 [     default task-21] [  STANDARD] [                    ] [                    ] (      internal.mgmt.Executable) INFO  frljbs700014.retraite.lan|null  - Popping initial executable for PRThread: STANDARD belonging to Requestor HVCPIRYK2JRMH9J3Y6ZET3TSPV50CDGTKA 

java.lang.Exception: null