What are the steps to trigger the problem? 1) refreshing the site

What happened? I get this error frequently:

An error occured while calling the Twitter API 500: {"errors":[{"message":"Internal error","code":131}]}

how to handle this problem??

The error is just that, twitter reported that they had an Internal Error when you made a request. You will likely find that this occurs when Twitter are having problems on their site too.