[Question] World with a world border throws an error

[LeadMagnet]

Not an issue, at least I don't think so.

I have one world. A 100 by 100 world used only by staff members for our server. Gives us a central place to make notes, store items, etc.

To make sure people don't use it for creative building (have another world for that! :P ) the world is a void world, 100 by 100 blocks in size. Main area is at Y64 (which I think is default) and 4 blocks deep (quartz if yer wondering). There is a world border around the area from bedrock to build height (you know how world borders work).

Anyway, was using 0.12.267 today, first run, and processed several worlds. Only this one threw an error:

WARNING:root:Unknown region type in ‘c:\MCWorlds\STAFFWorld

It threw the error twice, both back to back at the beginning, then proceeded to render the world (which is great by the way!). Took a tad over 2 minutes to render

The world looks fine. Everything visible is displayed. Looks like any other rendered world. Just perfect!

Has anybody else come across this error?