In order to have text blocks work correctly follow these steps:

Manage users access

Give your user profiles rights to use the following three objects, depending on your needs:

• Text Blocks
• Commitment Text Block Assignment
• Text Block MC Assignment

Correct Picklist Values

In order to make the language feature work you need to allign three language picklist fields:

1. Text Blocks.ADvendio__Language__c
2. Media Campaign.ADvendio__Quote_Language__c
3. Commitment.ADvendio__DocumentLanguage__c (careful this one is using 7.2.9.1 Picklist Values Sets (Global Picklists))

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:

Global Picklist: Language Code

Picklist: TextBlock.Language

Add Text Blocks to a Media Campaign

Add the related list "Assigned text blocks" to the Media Campagne page layout.

Add Text Blocks to a Commitment

Add the related list "Text blocks" to the Commitment page layout.