Feed posts are showing as black boxes with 'Feed not available' in the middle.

There are a couple of things that could be happening, causing your posts to no longer update automatically.

1. Let's clear the cache.

Then navigate to the feed and open the feed. It should automatically populate. 

If that gives you an error - please try the next step

2. Reconnect your account

Once you reconnect your account navigate to the feed setup and open the feed in question. That will automatically populate the posts. It is important to stay on this page until your posts have downloaded.