I had the same problem and I have resolved it by going through the following steps.

**If you need to keep your changes**  

 1. First you need to run `git checkout master` command to put you back to the master 
    branch.
 2. If you need to keep your changes just run `git checkout -b changes` and 
    `git checkout -B master changes`
 
**If you don't need your changes**

 1. To removes all untracked files from your branch run `git clean -df `.

 2. Then you need to clear all unstaged changes within your repository. In order to do that you have to run `git checkout -- `

 3. Finally you have to put your branch back to the master branch by using `git checkout master` command.