Content Transfer Tool : unable to stop data extraction

[cddeshmukh]

Hi, 

I wanted to try a sample asset migration for a folder (5-10 assets) using Content Transfer tool from an AMS instance to AEMasCS. I created a migration set and when I triggered extraction on AMS for that particular set, it is going on & on since long time. When checked the status, it shows below

When click on "stop extraction" that is also not working. Noticed below NullPointerException in the error.log 

Is there any way to stop this extraction process?