IGEL OS 10.04 IGEL OS Articles Browser Current: Some PDFs are not opened by Firefox PDF Download PDF Download page Some PDFs are not opened by Firefox. Current page All pages Some PDFs are not opened by Firefox SymptomWhen opening some PDFs from the Internet, the Mozilla Firefox browser opens a new window or tab, but fails to display the PDF contents.ProblemThis can be due to a malfunction of the mozplugger Firefox component.SolutionDisable mozplugger. Firefox will download the PDF document and open it with a local application (IGEL Linux 5.07.100 or newer):Go to System > Registry in IGEL Setup.Use Search Parameter ... to find the parameter browserglobal.app.dom_ipc_plugins_enabled_mozplugger_so.Check Completely disable mozplugger.Confirm the setting with Apply or OK.Restart Firefox. ×