Hello E4X and Interregnum players,
I've released a small, optional hotfix today that applies to both mods. An issue was discovered that caused the AI to occasionally stall and do very little. This was caused by a mostly behind the scenes change related to uncolonizeable planets made in Enhanced 4X version 1.7 (in part to test the ground for an unfinished Interregnum feature), but was not noticed at the time because of the Rebellion 1.8 patch had changed the AI as well.
This hotfix for the most part reverts that change, however this has the side effects of getting rid of the uncolonizeable planets' planet bonuses as well as the pirate trade station random encounter. The random trade stations will hopefully be back in the next full release, but the neutral planet bonuses were just not meant to be. I believe the future Interregnum feature can be accomplished in a different way that will not cause the AI problems.
To install this hotfix, simply extract the download. In that folder, there will be two folders, one which contains files for updating the Enhanced 4X Mod 1.73 and one for Interregnum. Simply copy the files in these folders and paste them to the GameInfo folder of the corresponding mod. Interregnum players will need to copy both sets of files into the correct mod. Additional instructions are included in a text file in the download.
I apologize for the inconvenience, and if you haven't had any problem with the AI you're free to wait for the next major release.