To diagnose a failure occurring on a link from a control's Properties call to a String service's Equals(), you must place breakpoints on the event links immediately before the failing link so you can inspect the values being passed (for example, the account number) and confirm whether a null is being propagated.

Pega Robot Studio debugging guidance:

''Breakpoints can be set on event links to pause execution at specific steps in an automation. During a paused state, developers can inspect the values on connected data ports to determine whether null or unexpected values are being passed to the next step.''

''Place breakpoints upstream of the failing event to verify the value retrieved from a control (for example, via a Properties call) before it is sent into a service method (such as Equals).''

Option A shows a breakpoint on the event path feeding the Properties block and another just before the segment that calls Equals(). This allows you to stop exactly where the input to Equals(string2) would be evaluated and verify whether it is null.

Option C also places a breakpoint directly on the event link leading into the Properties/Equals segment, which is the correct spot to pause and inspect the data value before the comparison occurs.

Options B, D, and E place breakpoints either too early (not reaching the Properties/Equals path yet) or on unrelated branches, which won't reliably expose the null value being passed into IStringService.Equals().