I rolled back the amd64-microcode to the previous version (3.20180524.1~ubuntu0.14.04.1 to 2.20131007.1+really20130710.1) and it resolved the issue, I can now boot to 151, so it is definitely related to amd64-microcode. I am using AMD Phenom(tm) II X4 975 Processor
I rolled back the amd64-microcode to the previous version (3.20180524. 1~ubuntu0. 14.04.1 to 2.20131007. 1+really2013071 0.1) and it resolved the issue, I can now boot to 151, so it is definitely related to amd64-microcode. I am using AMD Phenom(tm) II X4 975 Processor