Illustrator lagging badly after update 30.0

@silvia_8676 when you updated to the latest and greatest Illustrator, did you "mport previous settings and preferences?"—if you did, that might be the issue. While convenient, Ii an older preference setting is incompatible with new code in the latest version, it can cause application instability, freezes, or the kind of  Command Z lag you were experiencing! When installing a major new version of any Adobe app, always UNCHECK the box that says "Import previous settings and preferences." And start the new application with fresh, default preferences.

You have two choices:

• Reset the preferences will force the application to use the default settings that came with that new build, completely ignoring any potentially corrupted or incompatible imported settings from your old version. (Not sure if you are on a PC because you wrote Control Z for undo. But you also wrote MacBook Pro which is then Command Z!)
  
  To reset your Illustrator preferences to the clean, default settings for the new version, you can use a simple keyboard shortcut during launch. First, ensure the application is fully quit and not running in the background. Then, launch Illustrator again, and immediately upon clicking the app icon, press and hold the three-key combination: Shift Option Command (on Mac) or Shift Alt Ctrl (on PC). This action will trigger a crucial dialog box asking "Delete Adobe Illustrator Settings Files?" By clicking "Yes," you force the application to delete the old, potentially corrupted preference files, allowing Illustrator to open with all settings, including workspaces and shortcuts, restored to their stable, out-of-the-box defaults for version 30.0.
  
  
• Or roll back to a previous version that worked well for you