Some users have reported that you might get the following error message after updating TaxCalc for the Mac:

This is due to the security settings on the Mac. You can resolve this by going through the following steps:

1. Open the Finder.
2. Open the Applications folder.
3. Control-click or right-click the icon for the TaxCalc application.
4. Select Open from the top of contextual menu.

5. This opens another dialog box (as shown below).
6. Enter administrator credentials, if asked.

The program should now start as expected.

If this doesn’t work or the option is not available try the following steps:

1. Go to Apple menu (top left-hand corner of the screen) > System Preferences > Security & Privacy.
2. Select the General tab.
3. Under the header Allow apps downloaded from: you'll see the following options:

4. Click on the padlock and enter your credentials.
5. Change the radio button to Anywhere and click the padlock again.

You should now be able to open the program as intended.