Can't open Mac DMG

[uckelman]

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Issues with Download, Installation or Running being Blocked

Mac not being able to verify the Developer On a Mac you may get an error: “VASSAL cannot be opened because the developer cannot be verified. MacOS cannot verify that this app is free from malware.” Click Okay on such a dialog. [MacOS cannot verify that this app is free from malware.] If you have the current or a recent version of MacOS, Gatekeeper is probably active–MacOS will block VASSAL from running on the first attempt (because this isn’t what Apple considers a code-signed app). You’ll…