Bug: efcformcontroller-async-void-boundary-sinks-are-log-only

[drmoisan]

• Work Mode: full-bug

Summary

The five async void click handlers in EfcFormController route every caught failure into a
BoundaryErrorSink that defaults to a log-only delegate, so a failed button press writes a log entry
and shows the user nothing. The button appears to do nothing.

Environment

• OS/version: Windows 11, Outlook desktop (VSTO add-in host)
• Python version: not applicable; this is a .NET Framework 4.8.1 C# WinForms component
• Command/flags used: not reproducible from a command line; requires the Email Filer Combined form
• Data source or fixture: any condition that makes one of the five handler bodies throw

Steps to Reproduce

1. Open the Email Filer Combined form in Outlook with the TaskMaster add-in loaded.
2. Put the environment into a state that makes one of the five handler bodies throw, for example an unresolvable archive root.
3. Press the corresponding button.

Expected Behavior

A failure at a UI boundary either surfaces a redacted user-facing diagnostic or is a deliberate,
documented silent case. The user is not left unable to distinguish a failure from a no-op.

Actual Behavior

The exception is caught and passed to BoundaryErrorSink, whose default implementation writes to the
log only. Nothing is shown to the user and the control returns to an idle state, so the press is
indistinguishable from a no-op.

Logs / Screenshots

• Attached minimal logs or screenshot
• Snippet: not captured; the failure is visible only in the log4net output, which is the defect being reported.

Impact / Severity

• Blocker
• High
• Medium
• Low

Source

From: docs/features/potential/2026-08-29-efcformcontroller-async-void-boundary-sinks-are-log-only.md