Assuming that your internet connection is working correctly, your preferences for that app could be damaged. Perform some regular maintenance on your Mac, such as repairing permissions with Disk Utility. If that does not help, then search for the app plist file inside your user Library > Preferences. Generally the plist file contains the application name in it. For example: org.mozilla.firefox.plist, com.adobe.Acrobat.plist, etc. Quit the application that has the freezing problem. Then find the plist file and simply drag it to your desktop. Do not trash it! Then try to re-start the application. It'll re-create a brand new plist file. If the app works normally, then you will know the old plist was damaged. You can discard the old plist file safely.