Rule Formulas cannot access any entity fields for built-in User DB

[Matt_Blais]

NO entity fields are available for use in a Formula within a Rule on the built-in User DB.

E.g., try to create a Rule for the User DB that uses a Formula to update the value of a custom (user-added) field. It can’t be done.

You can turn the User Name into a Formula field, which works as expected (and that Formula can access the the User fields).
But you can’t do the Rule-based equivalent of this - using a Rule to update the User Name with a Formula.

[Polina_Zenevich]

Hi, Matt!
Screenshots would help a lot in fact
We failed to reproduce the issue

[Matt_Blais]

I cannot reference ANY fields in the User type here in this new Rule.

[Chr1sG]

You need to use [Step 1 User].[Last Name]

[Matt_Blais]

Doh!