it turns out that Kiwi Cattools can lock "C:\Program Files\Common Files\SolarWinds\wodssh.dll"
thus parking the install with a 'Code error: 4' as it is unable to copy a new version of wodssh.dll into the 'C:\Program Files\Common Files\SolarWinds'
Shutdown Cattools before attempting the upgrade..
hope this helps someone..
P