USB devices do not show up in VM

[Konstantin Vlasov]

Host OS: Windows 8.1 x64 VirtualBox 5.0.12

When I try to attach a USB device into VM it seems to get "stuck" or locked. When I click Devices->USB->My device (USB flash stick), I see it disappearing in the host OS, but it never appears in the guest OS (checked via dmesg: no messages at all about any new USB attachments). When I open that USB submenu again and hover my device, the tooltip tells that it is now "Captured", but there is no checkbox near the device name (which would indicate that the USB device is attached to the guest), and when I run VBoxManage showvminfo, it tells that there are no currently attached USB devices.

If I try to click the same device again, I get the error message that the device "is busy with a previous request". If I remove the device physically and reinsert it into another USB port, it appears in the USB menu as a new instance (while the previous one, the "Captured", remains there as well). However, clicking this new instance leads to absolutely the same behaviour: the device disappears from the host, never appears in the guest and remains forever locked in the "Captured" state.

[Konstantin Vlasov]

VBoxSVC log

[Konstantin Vlasov]

Virtual Machine log

[Konstantin Vlasov]

VM Hardening log (just in case)

[pham88]

I have this same problem. I'm using VirtualBox 5.0.15 r105767. I've also seen the problem on VirtualBox 5.0.14.

My Host OS is Windows 7. My Guest OS is Ubuntu 14.04.

I've attached my log files above.