Hello,
Assuming you are using MAC (as you mentioned about force Quit) i would suggest you to do go following location and launch Muse CC 2014 and then try to open file from File > Open.
1. Click on Finder > Go > Application
In the application folder look out for Muse CC 2014 and the launch Muse CC 2014 by double click.
If you are launching the correct Muse version its splash Screen would look like the image as below.
Image may be NSFW.
Clik here to view.
Regards
Vivek
