Sometimes, you need to adjust myTaxExpress/T2Express display option in Mac OS. Please follow these steps:
1. First, close myTaxExpress or T2Express; or use Force Quit to close myTaxExpress/T2Express
Select myTaxExpress/T2Express, then choose "Force Quit" button
2. Locate myTaxExpress or T2Express in the Applications folder, then right click the mouse
3. Choose menu "Show Package Contents", then double click "Wineskin" to run it.
4. Choose "Set Screen Options"
5. You can toggle "User Mac Driver instead of X11" option, one of them will work better for your computer.
6. Click the "Done" button to close the option dialog. Then click the top left "<" icon to go back to the Applications folder to run myTaxExpress/T2Express again.