I have a similar thing just a slightly different error.
“an I/O error occurred while installing a file. This is normally caused by bad installation media or a corrupt installation file.”
the error happens about 25% the way thought the 1.51 patch. when it get to the pakuo00.pk3 then a few seconds later bang the error pops up.
I have tried all of the above as I thought it sounded like the same thing but nothing worked.
Has an one got any idea how to fix