After reloading a game from the last autosave, several planets where I was upgrading Market Centers to Trade Centers show them as Market Centers with 0 weeks to completion. They have not completed even after many more turns. When I select the existing Market Center no options are shown for upgrading (i.e. I can't select Trade Center), while Trade Centers are available for building on other planets.
I have a saved game that hopefully could be used to illustrate the problem. If you want it, please let me know who to send it to.
