Credit to sjf for this. EDIT And 3 minutes after I posted this ticket I saw that ergwd had ticketed this a month ago.
See also https://ministry.kronosaur.com/record.hexm?id=72701

CommonwealthFleet.xml

The <Language> section doesn't have a <Text id= for the "actionDone" action used on Line 1352.

Needs
<Text id="actionDone">"[D]one"</Text>
on line 1373.

Or change the action id to "actionLeave" which has a text id.

nms 29 Jul 2017:

Better yet, with the improved inheritance, it should be possible for baCSCBase to inherit from dsDockscreenBase, right? Then a bunch of redundant text could be removed.

Edit: This doesn't work. But that should be fixed, right?

george moromisato 14 Sep 2017:

@NMS: I've changed it so baCSCBase inherits from unidCommonText. This solves the problem.

Thanks!