id,summary,reporter,owner,description,type,status,component,version,resolution,keywords,cc,guest,host 15969,VirtualBox 5.1.x Error for Windows 7 Guest: VERR_IEM_INSTR_NOT_IMPLEMENTED,BrettR,,"Windows 7 Guest was crashing on Mac OS X El Capitan 10.11.6 Host for VirtualBox versions 5.1.4 and 5.1.6. I tried installing a fresh copy of Windows 7 on both VirtualBox 5.1.x versions mentioned but would still experience VirtualBox fatal errors. Discovered these errors would occur when taxing the Windows 7 guest, particularly when using the Windows Update tool. I've tested VirtualBox 5.1.4/5.1.6 with a variety of settings, with subsequent fresh installs of Windows 7, but I experience these fatal errors no matter what. I rolled back to VirtualBox 4.3.40 to try and reproduce the VERR_IEM_INSTR_NOT_IMPLEMENTED fatal errors -- so far I've had no such issues. It would appear this bug stems from some addition to the 5.0 or 5.1 updates.",defect,closed,other,VirtualBox 5.1.6,duplicate,,,Windows,Mac OS X