This issue is observed when the NetScaler Gateway plug-in is not installed on the client computer. The NetScaler Gateway plug-in must be installed before performing EPA scans. The NetScaler Gateway plug-in installer includes a fragment of the EPA components. The installer registers this fragment with the 32-bit EPA COM server (nsepa.exe) and the NPAPI plugin DLL, 32-bit or 64-bit, as appropriate.
If a Gecko-based web browser, such as Firefox is already installed, the NPAPI plugin DLL is copied to the Mozilla Plugins folder under the application data folder of the user. For example, the plugin DLL is copied to the C:Documents and Settings<username>Application DataMozillaPlugins folder. If a Gecko-based web browser is not installed, Citrix plugins are registered to ensure that the plugins are discovered by the browser when it is installed.