So I did an upgrade as I did many times before on this model using a 1TB WD SSD and the appropriate thermal sensor from OWC. I transferred the data using migration assistant. After the transfer it booted up and all seemed OK, but some programs, such a Office for Mac 2011 did not open and/or triggered the shut down. I uninstalled Office and reinstalled it, and also did First Aid on the SSD, which came up fine. After that Office opened OK. However the random shutdowns recur still. The error report read like this:
* Panic Report ***
panic(cpu 2 caller 0xffffff801bbfea85): Kernel trap at 0xffffff801bbe6798, type 13=general protection, registers:
CR0: 0x0000000080010033, CR2: 0x000000010c3f7000, CR3: 0x0000000070415127, CR4: 0x00000000000226e0
RAX: 0xed0000720000ab00, RBX: 0x0000000000000000, RCX: 0xfffffedd40000000, RDX: 0xfffffe9d40000000
RSP: 0xffffff80272fbb90, RBP: 0xffffff80272fbbe0, RSI: 0x000ffffffffff000, RDI: 0x0000000000009146
R8: 0x0000000000000200, R9: 0xffffff80272fbd40, R10: 0x0000000000000000, R11: 0x0000000000000000
R12: 0x0000000000000000, R13: 0x260030090000ce00, R14: 0x0000000000000000, R15: 0x00007fff9708f000
RFL: 0x0000000000010287, RIP: 0xffffff801bbe6798, CS: 0x0000000000000008, SS: 0x0000000000000010
Fault CR2: 0x000000010c3f7000, Error code: 0x0000000000000000, Fault CPU: 0x2, PL: 1, VF: 0
Can anyone make sense of this? Cheers, Jurgen