Of note, I believe the new 2.1.20365 engine does not build new factories anymore, at least under certain maps. Previously played through a couple games under the scenarios The Rising Sun (Map v. 1.9.3) and 270BC (map v. 1.7.0) using the 1.9 engine and the AI would build plenty of factories or cities. We all updated and now they don't.
Hope this is the right place to put this. Also, ya'll have done great things with and for this game!