libvirt: error : unable to set AppArmor profile

I am following this tutorial on how to GPU passthrough, however when I get to about 6:43 mark, where you press the Begin Installation button, I get this following error:

Unable to complete install: 'internal error: Process exited prior to exec: libvirt:  error : unable to set AppArmor profile 'libvirt-5d739005-01d9-4c7c-9b41-bb3e3486c672' for '/usr/bin/qemu-system-x86_64': No such file or directory'  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/create.py", line 2119, in _do_async_install     guest.installer_instance.start_install(guest, meter=meter)   File "/usr/share/virt-manager/virtinst/installer.py", line 419, in start_install     doboot, transient)   File "/usr/share/virt-manager/virtinst/installer.py", line 362, in _create_guest     domain = self.conn.createXML(install_xml or final_xml, 0)   File "/usr/lib/python3/dist-packages/libvirt.py", line 3717, in createXML     if ret is None:raise libvirtError('virDomainCreateXML() failed', conn=self) libvirt.libvirtError: internal error: Process exited prior to exec: libvirt:  error : unable to set AppArmor profile 'libvirt-5d739005-01d9-4c7c-9b41-bb3e3486c672' for '/usr/bin/qemu-system-x86_64': No such file or directory 
➜ ls /usr/bin | grep qemu qemu-img qemu-io qemu-nbd qemu-pr-helper qemu-system-i386 qemu-system-x86_64 qemu-system-x86_64-spice 

I had been searching since yesterday on Google to find the solution but I can’t find anything on it. Does anyone here know why this error pops up?