libvirt.libvirtError: An error occurred, but the cause is unknow

Question

I am using XEN hypervisor. For managing virtual Machine I am using virt-manager whenever I want to start to Virtual Machine at last when everything is ready and I click the create Button I get the following error

Unable to complete install: 'An error occurred, but the cause is unknown'

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 75, in cb_wrapper
    callback(asyncjob, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/createvm.py", line 2089, in _do_async_install
    guest.installer_instance.start_install(guest, meter=meter)
  File "/usr/share/virt-manager/virtinst/install/installer.py", line 542, in start_install
    domain = self._create_guest(
  File "/usr/share/virt-manager/virtinst/install/installer.py", line 491, in _create_guest
    domain = self.conn.createXML(install_xml or final_xml, 0)
  File "/usr/lib/python3/dist-packages/libvirt.py", line 4034, in createXML
    if ret is None:raise libvirtError('virDomainCreateXML() failed', conn=self)
libvirt.libvirtError: An error occurred, but the cause is unknow

Answer 1

For the Xen driver, you may have more infos in /var/log/libvirt/libxl/libxl-driver.log

Answer 2

Same issue here.

When I check the /var/log/syslog, there is a log from libvirtd: "unsupported configuration: emulator '/usr/lib/xen-4.11/bin/qemu-system-i386' not found".

It may be caused by this bug. So we can create a symbolic link sudo ln -s /usr/bin/qemu-system-i386 /usr/lib/xen-4.11/bin/qemu-system-i386, and I hope it works for you too.

Answer 3

Check if you have installed qemu-system-x86-xen if not - install apt install qemu-system-x86-xen that helped me