SUMMARY Using Mac OSX 10.13.6. I downloaded the Krita .dmg, followed the installation steps, and when I tried to open the program for the first time, there was a loading bar that said it was "verifying" the program. Then I get the error " "Krita" is damaged and can't be opened. You should move it to the Trash." I deleted and re-downloaded the .dmg a few times and this happened every time. STEPS TO REPRODUCE 1. Download Mac version of Krita 4.4.5 2. Run installer 3. Open app OBSERVED RESULT App won't open and can't be used EXPECTED RESULT App would open and could be used SOFTWARE/OS VERSIONS Windows: macOS: 10.13.6 Linux/KDE Plasma: (available in About System) KDE Plasma Version: KDE Frameworks Version: Qt Version: ADDITIONAL INFORMATION
If this happens after you open the DMG file it is a problem on macOS 10.13: High Sierra is very old and the verification process fails on it. We no longer have a High Sierra system to identify what changed when we moved our build process to the an M1 mac, but since then High Sierra validation fails. You can delete the online validation by removing the "com.apple.quarantine" flag from krita.app after installing it. This will allow krita to open on your system.
See also https://www.youtube.com/watch?v=3py0kgq95Hk