Logic Pro X after update 10.7.9 not reacting, starting correctly nor using downloaded content.

Have you tried a restart of your computer?

What macos are you using?

What do you mean by: "I also removed the preference files and completely deleted the app and reinstalled it. Without success." and "(...) using duplicate services etc." ?

Create a backup or (at least) zip your old Logic app before updating.

Back up Logic Pro for Mac - Apple Support

Having load issues as well. When I open Logic, the information window appears, the software begins to search for new plugins to scan, and Logic crashes to a "Report" screen. I have uninstalled and reinstalled and still have the same issue. GarageBand is working fine.

Having similar issues. Upgraded to 10.7.9, and now I have intermittent display latency while working on projects. By this I mean that sometimes while working on a project, I open the stock EQ pluging on a track whilem playing, and the visual display is a beat or so behind the sound. Sometimes stopping and restarting playback fixes it, sometimes I have to quit Logic entirely. This is similar to the lag that Izotope Ozone introduces after you run an analysis. Turning off Ozone doesn't remove the lag, you have to remove the plug-in to remove the lag. It's also similar to the scrolling cursor lag when running Melodyne. This is asinine behavior and an absolute workflow killer for me, especially when I have deadlines, and especially after spending thousands of dollars to upgrade to the Mac Studio in the first place. I'm running a Mac Studio M1, 20cores, 128GB RAM and Ventura 13.4. Would love to get an answer that is not an AI-generated "My understanding is that you are having a problem with Logic. Have you tried restarting?" response. I know others are going through this.