'Critical Error' occurring regularly

[EW]

Hi,

I am running VirtualBox 5.1.18. The Host is a MacBook Pro running macOS Sierra. The Guest is running Windows 7. I am regularly getting a 'Critical Error' message and the guest is terminated.

"A critical error has occurred while running he virtual machine and the machine execution has been stopped."

No reason is given for this. Sometimes it happens immediately after log in, other times it can happen which the guest is idle, or when it is being used. I have attached the log as per the advice from the error message in the hope that someone can diagnose/assist? Thank you.

[mpack]

00:00:01.978374 Host RAM: 8192MB (8.0GB) total, 3865MB (3.7GB) available
...
00:00:02.128185 RamSize <integer> = 0x0000000100000000 (4 294 967 296, 4 096 MB, 4 GB)

Well, for one thing you are over-committing host RAM, which is not good.

But, your actual error is VERR_IEM_INSTR_NOT_IMPLEMENTED, which is a known problem with the 5.1.x branch on OS X hosts with modern Windows guests.

[EW]

Thank you mpack! I have reduced the RAM now (from 4GB to 3GB). Glad you were able to highlight the cause as the VERR_IEM_INSTR_NOT_IMPLEMENTED error. I guess I will need to wait for an update to resolve that. Thanks again!

[socratis]

VERR_IEM_INSTR_NOT_IMPLEMENTED error. I guess I will need to wait for an update to resolve that.

Or you can do as the sticky on the top of the forum suggests: 5.1.x Guru Meditation: VERR_IEM_INSTR_NOT_IMPLEMENTED

[EW]

Thank you, from this #forumNoob I've downgraded to 5.0.36 and it's been stable since.