1. Description: Boomerang Throwers can't be upgraded even with several ranged upgrades avaiable (currently have up to arquebusiers unlocked). Same thing with Faulua with up to Carrack unlocked.
2. Attachments: auto-save 5635.ctr
3. Steps to Reproduce: 1. Create a Faulua/Boomerang Thrower. Research a possible upgrade. 3.Verify unit eligibility to upgrade.
4. Expected Behavior: The unit should become eligible for upgrade once a more advanced unit of the same type is researched. 

Fauluas can only upgrade in the Industrial Era or later. I'll let you discover what they upgrade into. 

Indeed, i was quite anxious in my report.

I found out that Boomerang Throwers evolve into Line Infantry.

I wasn't able to pinpoint the exact upgrade, but it seems the Faulua's upgrade is indeed in the late Industrial Era, but since it took that long and i needed a faster ship at early modern i disbanded them to soak a bit of the population cost of a new ship. While having the culture ability of not taking damage for the lost at Sea, the reduced movement was becoming problematic.

Thanks for the kind replies.