I don't recommend using 3rd party applications to add items to your Facebook account because they might be infected with malware any other bad content. Always log-in on the service using your browser. However, if you encounter an issue with the Flash component that's because it's currently in a vulnerability mode which means it's not secure for your computer. When you add a picture, Facebook will also provide additional way. Use the classical way instead of the Flash one.
After this, uninstall Flash and wait for the Adobe to release a new update to fix the possible errors.