openclaw - 💡(How to fix) Fix [Bug]: Mattermost plugin fails to load after upgrading to 2026.4.2 — createSetupInputPresenceValidator is not a function [1 comments, 2 participants]

Bug type

plugin

Beta release blocker

Yes

Summary

After upgrading OpenClaw from 2026.4.1 (working) to 2026.4.2, the Mattermost plugin fails to load with TypeError: createSetupInputPresenceValidator is not a function, preventing all Mattermost communication.

Steps to reproduce

1. Have Mattermost plugin configured and working on OpenClaw 2026.4.1-beta.1
2. Run openclaw update to upgrade to 2026.4.2 (git commit 65c1716ad4)
3. Observe gateway startup failure with the error below

Expected behavior

Mattermost plugin loads and functions normally after upgrading OpenClaw, as it did on 2026.4.1-beta.1.

Actual behavior

Gateway fails to start the Mattermost plugin. Error in logs:

[plugins] mattermost failed to load from /home/luna/openclaw/extensions/mattermost/index.ts: TypeError: (0 , _setupRuntime.createSetupInputPresenceValidator) is not a function
  at maybeThrowOnPluginLoadError (file:///home/luna/openclaw/dist/pi-embedded-Bt2cc94B.js:3422:8)
  at loadOpenClawPlugins (file:///home/luna/openclaw/dist/pi-embedded-Bt2cc94B.js:3987:2)

OpenClaw version

2026.4.2 (git commit 65c1716ad4)

Operating system

Linux 6.12.74+deb13+1-amd64 (x64)

Install method

pnpm dev / git clone

Model

minimax/m2.7

Provider / routing chain

openclaw (local gateway) -> Mattermost server

Relevant config

"plugins": {
  "entries": {
    "mattermost": { "enabled": true }
  }
}

Logs, screenshots, and evidence

The error originates in /extensions/mattermost/src/setup-core.ts:

import { createSetupInputPresenceValidator } from "openclaw/plugin-sdk/setup-runtime";
// ...
validateInput: createSetupInputPresenceValidator({ ... })

Analysis:

• createSetupInputPresenceValidator is exported from src/channels/plugins/setup-helpers.ts line 245
• It is re-exported from src/plugin-sdk/setup-runtime.ts line 16
• However it does NOT appear in the compiled output at dist/plugin-sdk/setup-runtime.js (appears to be tree-shaken out during build)
• This function was present and working in OpenClaw 2026.4.1-beta.1

Impact and severity

• Affected: Mattermost channel users on OpenClaw 2026.4.2
• Severity: High — completely blocks Mattermost communication
• Frequency: 100% — every startup
• Consequence: Cannot use Mattermost as a channel; must fall back to webchat only

Additional information

Temporary workaround: set plugins.entries.mattermost.enabled = false in openclaw.json to allow gateway to start without the broken plugin.

Last known good: OpenClaw 2026.4.1-beta.1 First known bad: OpenClaw 2026.4.2

This is a regression caused by a SDK change that removed createSetupInputPresenceValidator from the compiled plugin-sdk output while the Mattermost plugin still depends on it.