"En" with the possessive

Question

For the example, we are told "Ta viande" cannot be put into an "en," yet "mes problèmes" can. How come the possessive can be an "en" in one case and not the other?

Maarten Kamp · Accepted Answer

Benjamin, this is nothing to do specifically with the possessive. 
In the lesson example ‘ ta viande..’ is not part of a prepositional adverbial phrase ‘ de ….. ‘ 
Compare the 2 examples directly :
1. Je m'occupe de mes problèmes. Je m’en occupe.
2. Ta viande est dans ton assiette. Pourquoi tu ne la manges pas ? (Without using the object pronoun ‘ la ‘, this would be “ Pourquoi tu ne mange pas ta viande ? “).
In the 2nd example, ‘ta viande’ is replaced by the direct object pronoun ‘la’, which also goes before the verb as usual, and not by an adverbial pronoun. 
There are links in the lesson covering the use of direct object pronouns, and the other adverbial pronoun ‘ y ‘.