id summary reporter owner description type status component version resolution keywords cc guest host 8018 upgrade to 4.0.0 causes host panic helix84 "Host: Debian Linux Lenny Guest: Debian Linux Lenny After upgrading from 3.2.12 to 4.0.0+extpack and starting one of the guests, I get a host panic. The only thing with relevant info I have is a screenshot of the host panic screen. I'll also attach VBox.log of the guest that caused the crash. I can provide any log files on request. Interestingly, another guest with the same OS runs fine. It crashed both when I started the guest both from VBoxHeadless and VirtualBox GUI, in the latter case I noticed the last thing the guest was doing was ""Setting up network..."" Both guests use the Am79C973 NIC. The host interfaces setup is as follows: Working guest -> tap -> br -> vlan Crashing guest -> vlanXY Luckily the downgrade to 3.2.12 works flawlessly." defect closed other VirtualBox 4.0.0 duplicate Linux Linux