iBank 4 is not supported with macOS Sierra, 10.12. The last supported version of OS X with iBank 4 was 10.8.5. We recommend upgrading to Banktivity 5 when using newer versions of OS X/macOS.
We have Support Articles that explain how to upgrade at the discounted price and how to import your iBank 4 data into Banktivity 5 with detailed steps. Here are the links:
Upgrade from iBank 4 to Banktivity 5 at a discounted price:
Upgrade iBank 4 data to Banktivity 5: