KB-XXXX Timer Event throws error "ERROR:EVAL:@reason=index"

Symptoms

A Timer Event with a valid expression-based delay throws an error when activated:

There is a problem with the process "Error on Timer"
Problem: An invalid expression has been encountered.

Details: ERROR:EVAL:@reason=index

Recommended Action: Check the expression including any function requirements and resume.

Priority of this problem: High Priority

Cause

This error occurs when keywords are used to pass in parameters to the expression used to specify the timer delay, for example:

rule!exampleRule(
 time: now(),
 timezone: "EST"
)

Timer event delays not supporting keyword parameters is a known limitation of the Appian product.

Action

Remove the keywords from the parameters passed into the timer delay expression, for example:

rule!exampleRule(
 now(),
 "EST"
)

Affected Versions

This article applies to all versions of Appian.

Last reviewed: November 2018