I needed to create a full-text index on a column, but I was unable to do so because of the following error: "Creation of the full-text index is not avaiable. Database is not enabled to allow for full-text indexing." After many hours of searching I found that Full-Text indexing is on by default. Well, not my case. I also found other suggestions of enabling them through the user interface, but I just couldn't find the option. After searching for a while, I found the query for enabling the feature:
EXEC sp_fulltext_database 'enable'
Of course you need to have the desired DB selected or...