One user has reported an issue opening the Screenwriter 6.5 installer .DMG (disk image) after they upgraded to macOS 12.13 High Sierra. The symptom is that after double-clicking the .dmg, the FInder puts up a "Verifying..." message, but the .DMG never mounts.
NOTE: this is DIFFERENT than a problem that occasionally happens on 10.11 El Capitan, where double-clicking the .pkg installer stalls during the verfication phase:
The High Sierra issue appears to be a known bug that Apple is aware of. There are a couple of options that may resolve this prior to Apple releasing 12.13.1:
1) Try restarting your mac, and trying to open the .DMG again.
2) Hold down the Control key when you click on the .dmg then select Open from the context menu. Theis should give you a window to "allow anyway".
If neither of these options solves the probelm for you, please make a Technical Support Request and let us know.
Tags: .dmg dmg High Sierra installer Movie Magic Screenwriter 6.5