Unable to save any watcher with an action of webhook as of Kibana 6.6

[ryanivis]

Kibana version:
6.6
Elasticsearch version:
6.6
Server OS version:
Ubuntu 16.04
Browser version:
Chrome / Firefox (doesn't matter for this bug)
Browser OS version:
(doesn't matter for this bug)
Original install method (e.g. download page, yum, from source, etc.):
apt-get
Description of the problem including expected versus actual behavior:
As of Kibana 6.6 you are unable to save watchers that include an action of 'webhook'. This is a MAJOR issue and needs to be fixed asap.

Steps to reproduce:

1. Open Kibana, create a new watcher, any watcher with action of 'webhook' will not save.

Errors in browser console (if relevant):
No Errors (but JavaScript Debug indicates the following)

vendors.bundle.dll.js:434 Error: Attempted to create unknown action type webhook. at JsonWatch.createAction (kibana.bundle.js:2) at kibana.bundle.js:2 at Array.forEach () at JsonWatchEditController.createActionsForWatch (kibana.bundle.js:2) at WatchEditTitleBarController.JsonWatchEditController._this.onWatchSave (kibana.bundle.js:2) at fn (eval at compile (vendors.bundle.dll.js:434), :4:212) at callback (vendors.bundle.dll.js:434) at Scope.$eval (vendors.bundle.dll.js:434) at Scope.$apply (vendors.bundle.dll.js:434) at HTMLButtonElement. (vendors.bundle.dll.js:434) at HTMLButtonElement.dispatch (vendors.bundle.dll.js:149) at HTMLButtonElement.elemData.handle (vendors.bundle.dll.js:149)

Provide logs and/or server output (if relevant):
Save action doesn't make it to Elastic, no server side logs generated.

Describe the feature:
Elastic Watchers

[ryanivis]

If the Kibana Engineers could take a look at this for us quickly, that would be excellent. This issue came up right after updating to 6.6. We have a ton of watchers utilizing web hooks and are unable to create new ones or modify any watcher integrating with webhooks.

Again this is impacting us significantly.

Thanks for the help!!!!

[elasticmachine]

Pinging @elastic/es-ui

[cjcenizal]

Hi @ryanivis! Thanks for reporting this. We've just merged a fix (#29818) into master, 6.x, and 6.6. You'll see it in 7.0.0, 6.7.0, and 6.6.1.