Business Rules have several quirky behaviors that will be addressed in a future release. Please read and understand these points before writing your first business rule. 

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Adding if (_data.getParameter('flow.activity.name') == "Step 1") to the Sales Planner Status rule, gives the expected results:

What causes an "Invalid signature detected. Data may have been tampered with" error?

This error message usually displays in multi-step workflows when there is a rule on a subsequent step that executes at form load and updates values inside a signed section in a previous step. Check your rules if you encounter this error.