How did you install? From the tar ball on the Fritizing install page or via a package manager? There are some issues with the git2 library at the moment (if it is too new things break and parts don't work which sounds like what is happening to you). The tar ball has an appropriate version included and works fine for me on Ubuntu Desktop. Note that if you uninstall manually, you need to remove the user directories as they are not touched during installation so upgrades won't affect your sketches, but will also cause problems to persist even after a reinstall.
are the two directories to remove. As well on first run, Fritzing updates the parts from github (which on Windows takes a long time and causes Fritzing to appear to freeze). If you interrupt that it often corrupts the user directories requiring they be deleted to fix it. I'd probably start by deleting the user directories and seeing if it starts working when run again.