at least that seems to show your problem is just with that one region.

You know that the other regions work OK as you can view and scroll over them.

Look up Rome's entry in descr_regions.txt and descr_strat.txt, and change the default faction and rebel type in descr_regions (3rd and 4th lines down) and the faction_creator in descr_strat.txt to the same combination of faction and rebel type that is in use and working for one of your other regions. If that fixes problem you can then experiment to see which bit it didn't like.

If you've got any loose rebel armies standing in province make sure the sub_faction you specified for them is also included as a proper faction with entry in the descr_strat.txt file.


Let me know how that goes, if it doesn't help I'll try and think of what else it could be...