I just installed a brand new ER-X at a customer site. Before installation, I upgraded it to v1.8.5.
As part of the install, I set a traffic policy on eth0 using the GUI Config Tree (Man, I love that tool)
The shaper for packets exiting the router went just fine. However, When setting the limiter for incoming packets, it threw errors. (sorry, did not record the error, but it has something to do with the "burst" requiring a "rate"). This is the same policy that we have running on other ER-Xs and indeed, when downgrading the OS to v1.8.0, the error went away and the limiter policy was set just fine.
Seems like an issue with v1.8.5