Hardware event. This is not a software error.
CPU 0 4 northbridge
Northbridge Watchdog error
bit57 = processor context corrupt
bit61 = error uncorrected
bus error 'generic participation, request timed out
generic error mem transaction
generic access, level generic'
STATUS b200000000070f0f MCGSTATUS 4
MCGCAP 105 APICID 0 SOCKETID 0
CPUID Vendor AMD Family 15 Model 47
Nothing there sounds good, it also doesn't point to any one specific thing.
Given that seems to be a >10yr old CPU, it's probably time to consider a replacement box.
AMD 0F 2F K8 (rev.E) Athlon 64 Sempron