Thank you all for your responses.
Karthik,
You suggestion helped with this issue. Apparently it was not due to deletion of queue nor deleting time stamp from delta tables. Somebody went and changed or point the server to a different one and due to several attempt to run extraction locked the system as well. I had been checking RFC connection and result was not producing successful every time. Sometimes test come back with no connection or shows check ok. That results also threw me out. BASIS team helped with this. All good now. Assigned points!!!
Thanks
Di