When I try to run the ArtPro installer on Mac OS 10.8 (Mountain Lion) or 10.9 (Mavericks), a message pops up stating that the installer is damaged.
Symptoms
Open the ArtPro 12.x Intel disk image.
Double-click ArtPro 12.x.mpkg to launch the installer.
A pop-up dialog appears, stating "‘ArtPro 12.x.mpkg’ is damaged and can’t be opened. You should move it to the Trash".
Solution
Do not immediately move the installer to the Trash. The installer may not actually be damaged. It may just be having problems with the new default security settings that were introduced in Mac OS 10.8.
Quit the ArtPro installer.
Go to the Mac System Preferences and open Security & Privacy.
Click the lock to make changes and enter the Administrator password.
Change the Allow applications downloaded from: setting to Anywhere.
Now re-launch the ArtPro installer and try to install ArtPro again.
Workaround
Should this not work, the installer may indeed be damaged. In that case, please make a new personalized build on the Download Center.