This could indicate that the software is having issues because of a few reasons:
The files are corrupted and the application causes a crash when a certain module is loaded (e.g. adding images, videos, music, etc).
The registry are corrupted and the software cannot locate the necessary files to load the next procedures.
Files you are trying to add are not supported or they're corrupted as well.
For all the causes, I recommend the immediate re-installation. To have a bigger chance of making it work, completely remove the software and then install it again.