A "Calling LoadLibraryEx on ISAPI filter "C:\Windows\Microsoft.NET\Framework\v4.0.30319\\aspnet_filter.dll" failed" Error Occurs When Loading A Laserfiche Web Application Hosted On A 64-bit Web Server.

March 10, 2014 | KB: 1013442
Audit Trail 8, Audit Trail 9, Web Access 8, Web Access 9,

Summary

When loading a Laserfiche Web application that is hosted on a 64-bit Web Server, you may receive the following error page:

    HTTP Error 500.0 - Internal Server Error

    Calling LoadLibraryEx on ISAPI filter "C:\Windows\Microsoft.NET\Framework\v4.0.30319\\aspnet_filter.dll" failed

Cause

IIS is incorrectly trying to load the 32-bit version of the ISAPI filter instead of the 64-bit version of the component.

Resolution

Modify ISAPI filter mappings for ASP.NET 4.0 to point to the 64-bit version of aspnet_filter.dll.

  1. Open the Internet Information Services (IIS) Manager.
  2. Select Default Web Site.
  3. In the center pane, double-click ISAPI Filters.
  4. Take note of the ASP.NET_4.0 entries. There may be three ASP.NET 4.0 entries:
    • ASP.Net_4.0
    • ASP.Net_4.0_32bit
    • ASP.Net_4.0_64bit
  5. Double-click the generic ASP.Net_4.0 entry and set the executable path to C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_filter.dll.