Sometimes you work with your changes through bitbucket online, after you open SourceTree on your local computer and after when you upload your changes, you can receive an error that some of the commits are not committed.
root@your-IP:/data/project-name # git pull
remote: Counting objects: 7, done.
remote: Compressing objects: 100% (5/5), done.
remote: Total 7 (delta 3), reused 0 (delta 0)
Unpacking objects: 100% (7/7), done.
269d0c6..ec9ffad master -> origin/master
error: Your local changes to the following files would be overwritten by merge:
Steps to resolve: Discard the local changes…