You may encounter this error message after you enter commands similar to these:

vyatta@vm-vrrp-pm-2# set vrrp vrrp-group 1 track path-monitor monitor monitor policy policy
[edit interfaces dataplane dp0p1s2]
vyatta@vm-vrrp-pm-2# commit
 
[interfaces dataplane dp0p1s2 vrrp vrrp-group 1 track path-monitor monitor monitor]

The full error message will look something like this:

The following path must exist:
  [service path-monitor monitor name monitor]
 
[[interfaces dataplane dp0p1s2 vrrp vrrp-group 1 track path-monitor monitor monitor]] failed.
 
Commit failed!