When starting up ArtPro+ on macOS Mojave (10.14), or when opening the file browser to open/place/save files, the computer seems to hang/freeze up for a few seconds.
These hangs/freezes are related to the new Security & Privacy implementation on macOS Mojave (10.14).
Startup and file browsing in ArtPro+ could react very slow in case the 'Allow the apps to control your computer' setting is enabled for 'Accessibility'.
This setting could have been enabled automatically or you have might have manually enabled it after seeing a similar message as the one below on macOS Mojave (10.14):
Symptoms
Starting up ArtPro+ immediately freezes your computer for about 5 seconds, or you notice delays or similar freezes/hangs when opening the file browser in ArtPro+ (i.e. to save, open or place files).
Solution
Go to System Preferences > Security & Privacy > Accessibility.
Under Allow the apps below to control your computer, make sure ArtPro+ is disabled.