Plug-In Manager handles
some of the web requests using Internet Server Application Programming
Interface (ISAPI). ISAPI is not compatible with Apache web server
versions 2.0.56 to 2.0.59 and versions 2.2.3 to 2.2.4.
If
your Apache web server runs any of the incompatible versions, you
can replace it with version. 2.0.63, which is the version that OfficeScan and Plug-In Manager are using. This version
is also compatible with ISAPI.