This one seems to only happen the first time a color is selected as part of the new gradient fill tools. If you open the color palette and click on the canvas when the color picker is not enabled, Black Ink crashes. If the color picker is enabled, or a color has already been selected and used to draw, Black Ink wont crash.
1. Fresh start BI
2. Select Linear Gradient Fill
3. Expand gradient detail window
4. Click on one of the color bubbles
5. Click color box under "colors" to open palette
6. Click anywhere inside palette or directly on picker icon to disable picker
7. Click on canvas