wont open On my Mac

I Trying to open Vassal on My Mac. I keep getting a message that I Cant open the app/file. because the developer cant be verified.
Please help! Thanks, Bob.

Open up “Finder”, and then type “Vassal” into the search line (I think in the upper right of the Finder window, right?). Then right-click (or Control click) on the Vassal program once you find it, and select Open. This time you will be given an option to go ahead and open the file.

Once you’ve done that, it will henceforth open correctly “the normal way”. It’s just a Mac safety feature with new apps.