Foundry376/Mailspring · error

EventHeader: Could not build RSVP reply: ${e.message}

Error message

EventHeader: Could not build RSVP reply: ${e.message}

What it means

Guard in EventHeader's RSVP button handler: EventRSVPTask.forReplying threw while building the reply task — most commonly because the current user is not listed as an attendee in icsOriginalData (the emailed .ics attachment), so no PARTSTAT can be set. Caught locally so the click doesn't crash the composer.

Source

Thrown at app/internal_packages/events/lib/event-header.tsx:301

      return;
    }

    // The attendee list in `icsOriginalData` (the emailed .ics attachment) can differ
    // from the one used to decide whether to show these buttons if a synced calendar
    // Event later replaced `icsEvent`. EventRSVPTask.forReplying throws if it can't
    // find us as an attendee in the data it's actually replying with; catch that here
    // instead of letting it crash the click handler.
    let task: EventRSVPTask;
    try {
      task = EventRSVPTask.forReplying({
        accountId: this.props.message.accountId,
        messageId: this.props.message.id,
        icsOriginalData,
        icsRSVPStatus: status,
        to: organizerEmail,
      });
    } catch (e) {
      console.warn(`EventHeader: Could not build RSVP reply: ${e.message}`);
      AppEnv.showErrorDialog(
        localized(
          "Sorry, we couldn't find your email address in this event's attendee list, so an RSVP reply could not be sent."
        )
      );
      return;
    }

    this.setState({ inflight: status });
    Actions.queueTask(task);
  };
}

export default EventHeader;

View on GitHub (pinned to 648c685d60)

Solutions

1. Reply to the invite via email instead of the RSVP buttons if you weren't a listed attendee
2. Ask the organizer to re-send the invite with your address as an attendee

When it happens

Trigger: Thrown at app/internal_packages/events/lib/event-header.tsx:301 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of Foundry376/Mailspring@648c685d60 (2026-09-03). Data as JSON: /api/errors/5baa737faff0eb89. Report an issue: GitHub.