The first time I try to save a concept it gives a spurious error about concept map type is required

When I try to create a concept with a mapping to a reference term, I get an error with this message:

Concept Map Type is required

I immediately click save a second time (without changing any information on the form) and it saves fine.

OpenMRS Version: 1.9.8 SNAPSHOT, also on 1.10.0 SNAPSHOT