This commit:
https://github.com/librenms/librenms/commit/62af66b49b4ff95146f74cef145eae61dbb98b58
Has caused a large number of my juniper devices (~25) to start spuriously reporting a failed routing engine.
It looks like in the code that was removed there was a filter that prevented some objects in the fru mib from being polled:
preg_match('/Routing Engine [0|1]/'
That has not been preserved in the YAML version.
I think the “right” way to implement the filter is to look at jnxFruSlot - it seems to be set to a negative number for the non-existent routing engines.