Closing as the issue only affects a Hardware Enablement Stack which is now End-of-Life. However, have opened bug #1345059 which is similar but far more serious as it affects the new Trusty HWE which is supported for the next three years and there is no current workaround.
Closing as the issue only affects a Hardware Enablement Stack which is now End-of-Life. However, have opened bug #1345059 which is similar but far more serious as it affects the new Trusty HWE which is supported for the next three years and there is no current workaround.