This article lists the known compatibility issues that you may encounter when running Illustrator CC on macOS 10.14 (Mojave).
When you enable the Dark appearance theme of macOS using System Preferences > General, the theme is not applied on Illustrator File menu dialogs that perform input and output operations. Instead, these dialogs are displayed in the Light theme.
The File input/output dialogs can be opened through the following menu options:
When you launch Illustrator, all launcher applications that run in the background, such as GPU Sniffer and Safe Mode, are docked in the dockbar along with Illustrator. macOS considers them as stand-alone applications and displays separate icons for them in the dockbar.
As a workaround, follow the steps below: