TypeError: 'null' is not an object : Sencha Architect V2.1.0 Build 678
Just updated to the latest Build 678 on Mac.
1. Start Sencha Architect: Choose Sencha Touch 2.1.x
2. Drag 2 container into view
3. Set first container to Card.
4. Click on second container. An unexpected error occured.
How do I revert back to the previous Build?
I can confirm that the above steps break in build 676 and 678. Going back to a previous build won't help you.
The problem is that you've set a card layout and the framework is expecting that it will have at least one item. This does not break in the current development branch for Sencha Architect 2.2.