I found a bug while authoring a business rule. Here are the repro steps:
Create a condition - condition 1
Yes - Show Error Message - Error message 1
Else If condition 2
Yes - Copy Error Message 1 and paste it here - change the message to Error Message 2
Save and activate the business rule.
Go to form and change field value to make condition 1 or 2 true - notice that the error message does not change correctly.
To workaround this - delete the Action /Show Error Message 2/. Add a new step (do not copy and paste) - /Show Error Message/ - Error Message 2.
Save and activate the business rule.
Now the business rule works correctly.
Looks like copy and paste for this Action /Show Error Message/ is reusing variable name for the error message in JavaScript and it's behaving erroneously during runtime. Please reach out to me if you have any questions.
Thanks,
Piyush