What is indicated by the error message "Expression evaluation error: Invalid variable(s) found: ri!name"?

The error message "Expression evaluation error: Invalid variable(s) found: ri!name" indicates that the reference to a Rule Input (ri) named "name" could not be resolved. This generally means that the Rule Input has not been defined within the context of the interface where it is being called. In Appian, if a variable is referenced but does not exist in the provided context, the system will produce an error to inform the developer that there is an issue with that specific input.

This error signifies that the system is unable to locate any definition or declaration for "name" as a Rule Input, leading to an expression evaluation failure. This could be due to a number of reasons, such as the input not being passed to the interface at the time of calling or simply being omitted from the interface's configuration.

The other options relate to different issues: an incorrectly defined interface variable usually suggests a flawed setup of the variable itself, a syntax error refers to discrepancies in the code's structure or format, and a data type issue pertains to mismatches in expected versus actual data types. However, none of these directly addresses the missing reference indicated in the error message.