>>1 ETQ200 Executing actual phase 'MAIN_DTTRANS/DOWNCONF_DTTRANS'.<<
In the logs you have supplied I can see the phase has been completed successfully. It has started the downtime phase. Most likely the GUI is stuck. Are there any logs that contain some information in the <Upgrade Directory>/SUM/abap/tmp location?
Can you list the latest 10 logs from the upgrade log location please?
Consider restarting the SUM tool and see what it says and if nothing helps a complete restart of the SAP system.