I have installed Oracle Linux 6.9 on a Virtualbox VM (Windows host) and ran a yum update to the Guest additions can be installed. The steps taken were:
# cd /etc/yum.repos.d
# mv public-yum-ol6.repo public-yum-ol6-old.repo
# wget http://yum.oracle.com/public-yum-ol6.repo
# yum update
# /usr/bin/ol_yum_configure.sh
The update creates a new version of the kernel Oracle Linux Server Unbreakable Kernel 2.6.39-400.308.1.el6uek, but when the VM is rebooted the start-up immediately fails displaying a stack dump (shown below). The older version of the kernel (294.3.el6uek.i686) still boots OK.

Any assistance would be appreciated please.
Andrew Wilkins