Re: Download Manifest Server Error
@JTGrimmfire I tried the first two downloads listed in your error log (Nora and Cecilia), and both downloaded and installed fine for me. I used Firefox and the Add to Game button, and everything looked fine, although I didn't load my game to check. Then I downloaded Harriet using Save File, and I managed to break the launcher's installer; a fourth downloaded sim (Cassie) refused to install with either method.
Point is, the downloads are working overall at the moment, although one or more of these sims may be corrupt enough to break the launcher. I would suggest trying to install them in a clean user folder, as a test, both to see whether you can in fact install them and whether they're broken in-game or come with custom content you don't want.