Error publishing workflow. There was an error in one of the content types chosen for a task action. Please ensure the content type selected for each task action is available on the site.

Hello,

I just tried to create the simple Approval Workflow to a document libray.

http://connect.nintex.com/files/folders/nw_for_office365_productguide/entry32265.aspx 

When ever I try to publish the workflow I do get the following message "

"

 I check everything, but can't figure out where the problem ist. I deleted all Tasks, except the first step. The problem still exists.

Any idear?