Perform the suggestions mentioned in the following articles: * [https://support.mozilla.com/en-US/kb/Template:clearCookiesCache/ Clear Cookies & Cache] * [[How to clear the cache#w_clear-the-cache|Clear the Network Cache]] * [[Using the Adobe Reader plugin with Firefox]] * [[Opening PDF files within Firefox]] Check and tell if its working. ------------------------------------------------------------------------------------------ -> Update All your Firefox Plugins * https://www.mozilla.org/en-US/plugincheck/ * '''When Downloading Plugins Update setup files, Remove Checkmark from Downloading other Optional Softwares with your Plugins (e.g. Toolbars, McAfee, Google Chrome, etc.)''' * Restart Firefox