...
fieldDescription
In order to increase security of our apps, we made a decision to remove the ability to add HTML content to the field descriptions. That will protect our users from malicious stuff that can be injected using XSS. We understand that may cause additional inconvenience for those who used this feature in 4.x versions of Power Actions. But we are doing that in order to make our products more reliable and trusted.
As an alternative you can use BA_createHtmlContent instead.