Looking closely at the title of the Synchronize view, see that it has started in Incoming Mode (see #1). This is because there are changes in the repository that should first be integrated before committing changes.
It is important to first update changes made to the repository, retest with those changes loaded locally with the soon to be committed changes and then commit the changes. By first taking the latest repository changes, and retesting, it helps to ensure that the changes about to be committed will actually work with the current state of the repository.