What does the error "Expression evaluation error: Invalid variable(s) found: ri!name" indicate in an Interface?

The error message "Expression evaluation error: Invalid variable(s) found: ri!name" indicates that there is a reference to a Rule Input that does not exist within the context of the interface. When building an interface in Appian, Rule Inputs (denoted by "ri!") are used to pass data into the interface. If the specified Rule Input, in this case, "name," is not defined in the interface's input parameters, the system cannot find it when evaluating the expression, leading to the error.

This situation commonly occurs when a developer expects certain inputs but forgets to declare them or makes a typo in the input name. The clear implication of the error message is that the expression is looking for a variable that has not been made available for use in the interface, thereby causing the evaluation to fail.

Understanding this error is essential because it emphasizes the importance of defining all needed inputs in an interface, ensuring that every variable referenced is properly declared and available for use in expressions.