Your first post shows the system reporting multiple problems with verifying software.  It is difficult to guess how the system has got into that condition.  To try to work out what is happening, please provide some context about what was happening before the problem started and what exactly changed between the last good update and the first time you encountered a problem ?

Having followed Jerry's suggestion in post 2 please can you rerun the update/upgrade process and post the results back so that we can see what effect (if any) applying the System Repair and then changing repositories has had.

Thank you.