WHEA uncorrectable error is a hardware malfunction usually related to the CPU. Try bringing the clock down and voltage alittle. If that doesn't work, lower the RAM frequency. If that doesn't work, check your CPU and if its mounted right.
I had the same problem and reseated my CPU and waterblock and it went away.
If none of the works, you may have to replace the cpu. (or at least swap it out and see if a new one works)