If it shows the log stops abruptly, there may be nothing in the setupact.log we can check to see what went wrong. If the system did a reboot and was not able to continue the log, there may have been a boot configuration or a driver situation which would not let it continue..
I have seen systems where their boot configuration had been modified by possibly another OS install of some type or they had used a third party software to set the boot configuration.
You could open your setuperr.log and look for that error and see if others show that might explain the situation, but beyond that, the setupact.log might be necessary. Sometimes we can find a reason but other times, we can't..