the worflow worked fine and suddenly this error appeared:
Webhook in action ‘Preño’ is attempting to invoke application ‘Milk Factory’ 0d71438b-d5c1-4299-bfdb-0eec4e532a4c but that application does not have an ‘ApplicationAccessKey’.
Cloud services are enabled and I have a new access key enabled, but it keeps showing error.
Actually, provided you have enabled the API via Manage > Integrations > IN: from cloud services to your app and you use a preset AppSheet API endpoint, you don’t need to specify the Application Access Key AFAIK.
I see the same problem and error on a couple of exising apps. @Phil should be expert for this issue.
In the meantime, it could be silly, but I sugget you try another shot by creating a new workflow from the scratch. Just an exactly same workflow. Then close (delete) the existing workflow set up to see how it goes.
This is what I did to clear my issue on my apps.
Have the same problem. Adding new keys, switching off old keys doesn’t help. After every change in the application need to refresh with Ctrl+F5 twice and errors are dissapeared, but than after next change, again get this errors.