When you install the software on a Mac, please do not launch the app from the mounted installer. You must drag the app folder into the Applications folder first.
When you run the dmg, you should be presented with a screen which saying something along the line of ‘drag the file over the the applications’ When you do so, go into your applications folder and run the software from there.
Another reason for the ‘templates.xml‘ error would be if you do not have full read & write permissions to the Applications folder. Please ensure that you have permissions for the Application folder.