In order to have text blocks work correctly follow these steps:
Give your user profiles to the following three objects, depending on your needs:
In order to make the language feature work you need to allign three language picklist fields:
The API names of the values in all three lists need to use the two character code for the language, i.e. en for English:
Add the related list "Assigned text blocks" to the Media Campagne page layout.
Add the related list "Text blocks" to the Commitment page layout.