What is one of the biggest problems that faced most African nations economies after they gained independence?

Te fact that their economy was totally dependent of the countries that colonized them. That is why most of these countries haven't economically developed so well. Additionally, even after gaining their independence, most of their industry was still in the hands of foreigners.

Explanation:

The whole African continent was under the control of European colonial powers. Most of the countries had peacefully gained their independence, but the problem was that they totally were depending on the economy of those countries. That is why this process of economical deliberation lasted for a longer period of time.