prime 95 says hardware error need help solving

[OCD Tweaker]

my build
asus z170-ar
i5 6600k (OC to 4.5ghz at 1.255 Volts) EDIT(while running prime 95 CPUZ had my volts at 1.264v)
33c idle the cores are around 60c no higher under-load
8gb ddr4 2400
gtx 1070 g1
850W ax PSU

the only thing i changed in my bios was the voltage and the core ratio nothing else

i'm running prime 95 for about 10 mins it kept saying pass pass pass on all the cores
assuming that's what the 4 windows inside the big window means
i open up the local file it says hardware FAILURE open stress.txt for more information

LOL it says ask yall

i'm using MSI afterburner to monitor everything

and i noticed that one of my core temps was 40c when the other ones were around 49c and higher. i scroll down just a tad bit more and i noticed the core is only working about 48%

i'm assuming that's my hardware failure....

do i need to increase my volts to my CPU to get that core back up OR DID i BLOW OUT A CORE

 

[OCD Tweaker]

SO i restored my bios to default running prime 95 turns out it was a voltage issue

i really dont want to go to 1.3V just because i want to keep this CPU

is there anything i should change in my bios other than voltages and core ratio

 

[damric]

Intel rates Skylake processors up to 1.52v, so I don't know what you are worried about.