Had Obsidian 0.12.3 installed, made custom configuration, including using light theme, gruvbox theme, and installed several plugins. Have only one vault. I noticed the app is updated to 0.12.4. automatically. The theme is returned to dark and all plugins were gone. Plugin subfolders are still in the ~/.obsidian/plugins/ folder but not loaded in the app.
What I meant is that after the update, when the program is loaded, the interface showed the Help vault, not the working vault before the update. I guess we are talking about the same thing.