Use this query to see what all is running on the DB and see where you might have lock conflicts
SELECT SESSION_ID, START_TIME, BLOCKING_SESSION_ID, STATUS,COMMAND, WAIT_TYPE, LAST_WAIT_TYPE, WAIT_TIME, ST.text--, QP.query_plan FROM SYS.DM_EXEC_REQUESTS as ER CROSS APPLY sys.dm_exec_sql_text(ER.sql_handle) as ST --CROSS APPLY sys.dm_exec_text_query_plan(ER.plan_handle,0,-1) as QP WHERE ER.SESSION_ID > 50