Being unable to change your Project name (in the Project Settings screen) may happen if you have an additional custom 'title' reference Tag. The capitalized 'Title' Tag is the default field where the titles of your references should be placed. This duplicate "title" Tag (note the lowercase 't') will prevent the saving of your Project Settings.
To resolve this issue:
- Go to References > Formats > Delete Fields.
- Find your 'title' field.
- Select 'title' and delete the field.
- Go to Project > Project Settings, change your Project name and click Submit.
- Verify that your changes were saved.